equipment/soft for 240Hz refresh rate

1
Hello,
I am a beginner and I have probably basic question.
We plan to run motion detection experiment that requires very high time resolution.  For this I think to purchase a monitor with the highest available refresh rate (BenQ Zowie XL2540,  4.5" 16:9 1920 x 1080 TN 240Hz ).   Will Psychotoolbox be able to handle such a high resolution and what graphic card we would need for that?  What operational system (Linux, Mac, Windows) would be preferable?
Any tips would be very valuable!
Elena


2
XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :

Hello,
I am a beginner and I have probably basic question.
We plan to run motion detection experiment that requires very high time resolution.  For this I think to purchase a monitor with the highest available refresh rate (BenQ Zowie XL2540,  4.5" 16:9 1920 x 1080 TN 240Hz ).   Will Psychotoolbox be able to handle such a high resolution and what graphic card we would need for that?  What operational system (Linux, Mac, Windows) would be preferable?
Any tips would be very valuable!
Elena


-> Hi Elena,


PTB itself can handle that if the underlying OS/hardware can. I strongly recommend Linux, especially for such demanding tasks. But achieving 240 Hz redraw rate consistently without glitches is pushing hard, so even small misconfiguration of the hardware or software, or one sub-standard hardware component in your machine, or slightly suboptimal experiment code could ruin it. I haven't ever run anything at 240 Hz with vsync enabled, as required for proper visual stimulation, due to lack of any suitable displays. In terms of pure graphics performance it isn't a problem for not too complex stimuli, e.g., rendering 1000 fps on average is pretty doable even on on six year old graphics cards. Doing it vsync'ed, with stable refresh and no frame drops is a different issue.


I would recommend a PTB supported/tested Linux distro, e.g., atm. Ubuntu 16.04-LTS or one of its flavors, with a upper end AMD graphics card, using the open-source graphics/display drivers. There are more modern AMD cards available nowadays which should also work, but the most recent card i was able to test with good performance is the AMD Radeon R9 380 "Tonga pro". That one reliably drives a 120 Hz Viewpixx display at 1920x1080 and easily managed simulated 1440 Hz at 960x540 pixels for driving a Propixx projector in its special 12x 120 Hz -> 1440 Hz mode.


The nice thing about Linux with the open-source graphics drivers is that it supports a special mode which allows to use triple-buffering and precise timestamping at the same time, as demonstrated in PerceptualVBLSyncTestFlipInfo2.m. Thereby you get extra robustness for high framerates due to the triple-buffering, but still trustworthy timestamps for actually checking if your presentation timing was correct during a trial.


However, some tweaking might be required even on Linux with well working hardware, so choice of hardware and software would only be a starting point. Badly configured PC hardware could ruin it even if you basically do everything right. It also depends a lot on the complexity of your stimuli. So this is just a recommendation for a starting point, not a guarantee it will work out of the box, or - if you are unlucky - at all with a specific type of PC hardware or graphics card.


best,

-mario


3
Thank you Mario for the detailed information, very useful!

I understand that having good 240 Hz screen refresh may be a challenge.
There are now different monitors on the market that give >120 Hz, e.g. 144 Hz.

What is the highest refresh rate that would stably work in PTB ?

Best,
Elena

On 9 December 2016 at 04:39, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


Hello,
I am a beginner and I have probably basic question.
We plan to run motion detection experiment that requires very high time resolution. For this I think to purchase a monitor with the highest available refresh rate (BenQ Zowie XL2540, 4.5" 16:9 1920 x 1080 TN 240Hz ). Will Psychotoolbox be able to handle such a high resolution and what graphic card we would need for that? What operational system (Linux, Mac, Windows) would be preferable?
Any tips would be very valuable!
Elena


-> Hi Elena,


PTB itself can handle that if the underlying OS/hardware can. I strongly recommend Linux, especially for such demanding tasks. But achieving 240 Hz redraw rate consistently without glitches is pushing hard, so even small misconfiguration of the hardware or software, or one sub-standard hardware component in your machine, or slightly suboptimal experiment code could ruin it. I haven't ever run anything at 240 Hz with vsync enabled, as required for proper visual stimulation, due to lack of any suitable displays. In terms of pure graphics performance it isn't a problem for not too complex stimuli, e.g., rendering 1000 fps on average is pretty doable even on on six year old graphics cards. Doing it vsync'ed, with stable refresh and no frame drops is a different issue.


I would recommend a PTB supported/tested Linux distro, e.g., atm. Ubuntu 16.04-LTS or one of its flavors, with a upper end AMD graphics card, using the open-source graphics/display drivers. There are more modern AMD cards available nowadays which should also work, but the most recent card i was able to test with good performance is the AMD Radeon R9 380 "Tonga pro". That one reliably drives a 120 Hz Viewpixx display at 1920x1080 and easily managed simulated 1440 Hz at 960x540 pixels for driving a Propixx projector in its special 12x 120 Hz -> 1440 Hz mode.


The nice thing about Linux with the open-source graphics drivers is that it supports a special mode which allows to use triple-buffering and precise timestamping at the same time, as demonstrated in PerceptualVBLSyncTestFlipInfo2 .m. Thereby you get extra robustness for high framerates due to the triple-buffering, but still trustworthy timestamps for actually checking if your presentation timing was correct during a trial.


However, some tweaking might be required even on Linux with well working hardware, so choice of hardware and software would only be a starting point. Badly configured PC hardware could ruin it even if you basically do everything right. It also depends a lot on the complexity of your stimuli. So this is just a recommendation for a starting point, not a guarantee it will work out of the box, or - if you are unlucky - at all with a specific type of PC hardware or graphics card.


best,

-mario



4



XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :

Thank you Mario for the detailed information, very useful!

I understand that having good 240 Hz screen refresh may be a challenge.
There are now different monitors on the market  that give >120 Hz, e.g. 144 Hz.

What is the highest refresh rate that would stably work in PTB ?

-> That's completely dependent on the quality of the underlying operating system, hence my recommendation for Linux, and the performance and quality of the graphics card and PC hardware. 120 Hz work perfectly reliable on the configuration i told you, i'd assume 144 Hz as well, but i couldn't test that. I'd hope 240 Hz as well, possibly with some tweaking, but without the ability to test that i can't guarantee anything. It obviously also depends on the complexity of your stimuli, if you have to do other things in parallel like sound i/o, keyboard queries, digital i/o etc. - things that take up time in the main stimulation loop, and how efficiently you implement your code.

PTB can stimulate on that Linux setup stably with 1440 Hz, but only with a special - and expensive - Propixx projector and proper coding, so that won't apply to the 240 Hz display you suggested.

You would have to describe what kind of stimuli you intend to present.

What i recommended you gives you a good chance of working, but you may need to come back for tweaking instructions if it doesn't work out of the box. Or you might need an even more high-end card, if you have very complex stimuli. And no guarantees of course.

-mario

Best,
Elena

On 9 December 2016 at 04:39, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:
 

XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


Hello,
I am a beginner and I have probably basic question.
We plan to run motion detection experiment that requires very high time resolution.  For this I think to purchase a monitor with the highest available refresh rate (BenQ Zowie XL2540,  4.5" 16:9 1920 x 1080 TN 240Hz ).   Will Psychotoolbox be able to handle such a high resolution and what graphic card we would need for that?  What operational system (Linux, Mac, Windows) would be preferable?
Any tips would be very valuable!
Elena


-> Hi Elena,


PTB itself can handle that if the underlying OS/hardware can. I strongly recommend Linux, especially for such demanding tasks. But achieving 240 Hz redraw rate consistently without glitches is pushing hard, so even small misconfiguration of the hardware or software, or one sub-standard hardware component in your machine, or slightly suboptimal experiment code could ruin it. I haven't ever run anything at 240 Hz with vsync enabled, as required for proper visual stimulation, due to lack of any suitable displays. In terms of pure graphics performance it isn't a problem for not too complex stimuli, e.g., rendering 1000 fps on average is pretty doable even on on six year old graphics cards. Doing it vsync'ed, with stable refresh and no frame drops is a different issue.


I would recommend a PTB supported/tested Linux distro, e.g., atm. Ubuntu 16.04-LTS or one of its flavors, with a upper end AMD graphics card, using the open-source graphics/display drivers. There are more modern AMD cards available nowadays which should also work, but the most recent card i was able to test with good performance is the AMD Radeon R9 380 "Tonga pro". That one reliably drives a 120 Hz Viewpixx display at 1920x1080 and easily managed simulated 1440 Hz at 960x540 pixels for driving a Propixx projector in its special 12x 120 Hz -> 1440 Hz mode.


The nice thing about Linux with the open-source graphics drivers is that it supports a special mode which allows to use triple-buffering and precise timestamping at the same time, as demonstrated in PerceptualVBLSyncTestFlipInfo2 .m. Thereby you get extra robustness for high framerates due to the triple-buffering, but still trustworthy timestamps for actually checking if your presentation timing was correct during a trial.


However, some tweaking might be required even on Linux with well working hardware, so choice of hardware and software would only be a starting point. Badly configured PC hardware could ruin it even if you basically do everything right. It also depends a lot on the complexity of your stimuli. So this is just a recommendation for a starting point, not a guarantee it will work out of the box, or - if you are unlucky - at all with a specific type of PC hardware or graphics card.


best,

-mario



5
Dear Mario,
Thank you again for the guidance.

Since we are going to use very simple stimuli (black and white gratings) without sound, there is some hope that 240 Hz will work with the configuration you suggested.

If not, do you think we still can use the same 240 Hz monitor at 120Hz mode?

My other question is how can we test the timing precision in PTB to be sure that we have truly 240 Hz refresh and that there are no frames missed?

Best,
Elena

On 9 December 2016 at 23:11, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:




XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :

Thank you Mario for the detailed information, very useful!

I understand that having good 240 Hz screen refresh may be a challenge.
There are now different monitors on the market that give >120 Hz, e.g. 144 Hz.

What is the highest refresh rate that would stably work in PTB ?

-> That's completely dependent on the quality of the underlying operating system, hence my recommendation for Linux, and the performance and quality of the graphics card and PC hardware. 120 Hz work perfectly reliable on the configuration i told you, i'd assume 144 Hz as well, but i couldn't test that. I'd hope 240 Hz as well, possibly with some tweaking, but without the ability to test that i can't guarantee anything. It obviously also depends on the complexity of your stimuli, if you have to do other things in parallel like sound i/o, keyboard queries, digital i/o etc. - things that take up time in the main stimulation loop, and how efficiently you implement your code.

PTB can stimulate on that Linux setup stably with 1440 Hz, but only with a special - and expensive - Propixx projector and proper coding, so that won't apply to the 240 Hz display you suggested.

You would have to describe what kind of stimuli you intend to present.

What i recommended you gives you a good chance of working, but you may need to come back for tweaking instructions if it doesn't work out of the box. Or you might need an even more high-end card, if you have very complex stimuli. And no guarantees of course.

-mario

Best,
Elena

On 9 December 2016 at 04:39, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


Hello,
I am a beginner and I have probably basic question.
We plan to run motion detection experiment that requires very high time resolution. For this I think to purchase a monitor with the highest available refresh rate (BenQ Zowie XL2540, 4.5" 16:9 1920 x 1080 TN 240Hz ). Will Psychotoolbox be able to handle such a high resolution and what graphic card we would need for that? What operational system (Linux, Mac, Windows) would be preferable?
Any tips would be very valuable!
Elena


-> Hi Elena,


PTB itself can handle that if the underlying OS/hardware can. I strongly recommend Linux, especially for such demanding tasks. But achieving 240 Hz redraw rate consistently without glitches is pushing hard, so even small misconfiguration of the hardware or software, or one sub-standard hardware component in your machine, or slightly suboptimal experiment code could ruin it. I haven't ever run anything at 240 Hz with vsync enabled, as required for proper visual stimulation, due to lack of any suitable displays. In terms of pure graphics performance it isn't a problem for not too complex stimuli, e.g., rendering 1000 fps on average is pretty doable even on on six year old graphics cards. Doing it vsync'ed, with stable refresh and no frame drops is a different issue.


I would recommend a PTB supported/tested Linux distro, e.g., atm. Ubuntu 16.04-LTS or one of its flavors, with a upper end AMD graphics card, using the open-source graphics/display drivers. There are more modern AMD cards available nowadays which should also work, but the most recent card i was able to test with good performance is the AMD Radeon R9 380 "Tonga pro". That one reliably drives a 120 Hz Viewpixx display at 1920x1080 and easily managed simulated 1440 Hz at 960x540 pixels for driving a Propixx projector in its special 12x 120 Hz -> 1440 Hz mode.


The nice thing about Linux with the open-source graphics drivers is that it supports a special mode which allows to use triple-buffering and precise timestamping at the same time, as demonstrated in PerceptualVBLSyncTestFlipInfo2 .m. Thereby you get extra robustness for high framerates due to the triple-buffering, but still trustworthy timestamps for actually checking if your presentation timing was correct during a trial.


However, some tweaking might be required even on Linux with well working hardware, so choice of hardware and software would only be a starting point. Badly configured PC hardware could ruin it even if you basically do everything right. It also depends a lot on the complexity of your stimuli. So this is just a recommendation for a starting point, not a guarantee it will work out of the box, or - if you are unlucky - at all with a specific type of PC hardware or graphics card.


best,

-mario




6
XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :

Dear Mario,
Thank you again for the guidance.

Since we are going to use very simple stimuli  (black and white gratings) without sound, there is some hope that 240 Hz will work with the configuration you suggested.

If not, do you think we still can use the same 240 Hz monitor  at 120Hz mode?

-> You can run it at 1920x1080 240 Hz video mode and just flip your stimuli every 2nd frame, so you get effective 120 fps, e.g., like demonstrated in VBLSyncTest([],2);

My other question is how can we test the  timing precision in PTB to be sure that we have truly 240 Hz refresh and that there are no frames missed?

If PTB doesn't complain about timing trouble with error or warning messages - and it shouldn't ever on a properly set up Linux system with the open-source display drivers - then the stimulus onset timestamps returned by Screen('Flip') are very trustworthy and almost micro-second accurate. VBLSyncTest.m shows again how to check for skipped frames and proper timing.

One thing to keep in mind is that the software can only time-stamp what leaves the video output of your computer, not what the actual display is doing. That's why it is often important to run the panel at its native resolution and refresh rate, as various panels do weird things at lower refresh rates, or non-native resolutions.

best,
-mario


Best,
Elena

On 9 December 2016 at 23:11, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:
 




XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :

Thank you Mario for the detailed information, very useful!

I understand that having good 240 Hz screen refresh may be a challenge.
There are now different monitors on the market  that give >120 Hz, e.g. 144 Hz.

What is the highest refresh rate that would stably work in PTB ?

-> That's completely dependent on the quality of the underlying operating system, hence my recommendation for Linux, and the performance and quality of the graphics card and PC hardware. 120 Hz work perfectly reliable on the configuration i told you, i'd assume 144 Hz as well, but i couldn't test that. I'd hope 240 Hz as well, possibly with some tweaking, but without the ability to test that i can't guarantee anything. It obviously also depends on the complexity of your stimuli, if you have to do other things in parallel like sound i/o, keyboard queries, digital i/o etc. - things that take up time in the main stimulation loop, and how efficiently you implement your code.

PTB can stimulate on that Linux setup stably with 1440 Hz, but only with a special - and expensive - Propixx projector and proper coding, so that won't apply to the 240 Hz display you suggested.

You would have to describe what kind of stimuli you intend to present.

What i recommended you gives you a good chance of working, but you may need to come back for tweaking instructions if it doesn't work out of the box. Or you might need an even more high-end card, if you have very complex stimuli. And no guarantees of course.

-mario

Best,
Elena

On 9 December 2016 at 04:39, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:
 

XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


Hello,
I am a beginner and I have probably basic question.
We plan to run motion detection experiment that requires very high time resolution.  For this I think to purchase a monitor with the highest available refresh rate (BenQ Zowie XL2540,  4.5" 16:9 1920 x 1080 TN 240Hz ).   Will Psychotoolbox be able to handle such a high resolution and what graphic card we would need for that?  What operational system (Linux, Mac, Windows) would be preferable?
Any tips would be very valuable!
Elena


-> Hi Elena,


PTB itself can handle that if the underlying OS/hardware can. I strongly recommend Linux, especially for such demanding tasks. But achieving 240 Hz redraw rate consistently without glitches is pushing hard, so even small misconfiguration of the hardware or software, or one sub-standard hardware component in your machine, or slightly suboptimal experiment code could ruin it. I haven't ever run anything at 240 Hz with vsync enabled, as required for proper visual stimulation, due to lack of any suitable displays. In terms of pure graphics performance it isn't a problem for not too complex stimuli, e.g., rendering 1000 fps on average is pretty doable even on on six year old graphics cards. Doing it vsync'ed, with stable refresh and no frame drops is a different issue.


I would recommend a PTB supported/tested Linux distro, e.g., atm. Ubuntu 16.04-LTS or one of its flavors, with a upper end AMD graphics card, using the open-source graphics/display drivers. There are more modern AMD cards available nowadays which should also work, but the most recent card i was able to test with good performance is the AMD Radeon R9 380 "Tonga pro". That one reliably drives a 120 Hz Viewpixx display at 1920x1080 and easily managed simulated 1440 Hz at 960x540 pixels for driving a Propixx projector in its special 12x 120 Hz -> 1440 Hz mode.


The nice thing about Linux with the open-source graphics drivers is that it supports a special mode which allows to use triple-buffering and precise timestamping at the same time, as demonstrated in PerceptualVBLSyncTestFlipInfo2 .m. Thereby you get extra robustness for high framerates due to the triple-buffering, but still trustworthy timestamps for actually checking if your presentation timing was correct during a trial.


However, some tweaking might be required even on Linux with well working hardware, so choice of hardware and software would only be a starting point. Badly configured PC hardware could ruin it even if you basically do everything right. It also depends a lot on the complexity of your stimuli. So this is just a recommendation for a starting point, not a guarantee it will work out of the box, or - if you are unlucky - at all with a specific type of PC hardware or graphics card.


best,

-mario




7
Hi Mario,
we purchased a PC with AMD Radeon R9 380 "Tonga pro", installed Ubuntu 16.04-LTS and tried to use it with
the 240 Hz display (BenQ Zowie XL2540, 4.5" 16:9 1920 x 1080 TN 240Hz ). We installed the Linux drivers from
AMDGPU-Pro Driver Version 16.50 for Ubuntu 16.04


It seems to fail (as you can see from the text below). Moreover, the refresh rate it gives is only 60 Hz.

It there any way or should we try another monitor?

Elena



PTB-INFO: Display ':0' : X-Screen 0 : Assigning primary output as 0 with RandR-CRTC 0 and GPU-CRTC 0.

PTB-INFO: This is Psychtoolbox-3 for GNU/Linux X11, under Matlab 64-Bit (Version 3.0.12 - Build date: May 13 2016).
PTB-INFO: Support status on this operating system release: Linux 4.4.0-53-lowlatency Supported.
PTB-INFO: Type 'PsychtoolboxVersion' for more detailed version information.
PTB-INFO: Most parts of the Psychtoolbox distribution are licensed to you under terms of the MIT License, with
PTB-INFO: some restrictions. See file 'License.txt' in the Psychtoolbox root folder for the exact licensing conditions.

PTB-INFO: Advanced Micro Devices, Inc. [AMD/ATI] - Tonga PRO [Radeon R9 285/380] GPU found. Trying to establish low-level access...
PTB-INFO: Connected to Advanced Micro Devices, Inc. [AMD/ATI] Tonga PRO [Radeon R9 285/380] GPU with DCE-10.0 display engine [6 heads]. Beamposition timestamping enabled.
PTB-DEBUG:PsychOSGetSwapCompletionTimestamp: Invalid return values ust = 0, msc = 0 from call with success return code (sbc = 20)! Failing with rc = -2.
PTB-DEBUG:PsychOSGetSwapCompletionTimestamp: This likely means a driver bug or malfunction, or that timestamping support has been disabled by the user in the driver!

...

PTB-INFO: OpenGL-Renderer is ATI Technologies Inc. :: AMD Radeon R9 200 Series :: 4.5.13462 Compatibility Profile Context 16.50.5
PTB-INFO: VBL startline = 1080 , VBL Endline = 1123
PTB-INFO: Measured monitor refresh interval from beamposition = 16.667021 ms [59.998726 Hz].
PTB-INFO: Will try to use OS-Builtin OpenML sync control support for accurate Flip timestamping.
PTB-INFO: Measured monitor refresh interval from VBLsync = 16.661187 ms [60.019732 Hz]. (294 valid samples taken, stddev=0.554106 ms.)
PTB-INFO: Reported monitor refresh interval from operating system = 16.666667 ms [60.000000 Hz].
PTB-INFO: Small deviations between reported values are normal and no reason to worry.
PTB-DEBUG:PsychOSGetSwapCompletionTimestamp: Invalid return values ust = 0, msc = 0 from call with success return code (sbc = 305)! Failing with rc = -2.
PTB-DEBUG:PsychOSGetSwapCompletionTimestamp: This likely means a driver bug or malfunction, or that timestamping support has been disabled by the user in the driver!
PTB-WARNING:PsychOSGetSwapCompletionTimestamp() FAILED: errorcode = -2, tSwapComplete = 0.000000.
PTB-WARNING: If this message shows up frequently during sessions, instead of only very sporadically, then
PTB-WARNING: this likely means that timestamping will *not work at all* and has to be considered
PTB-WARNING: not trustworthy! Check your system configuration, e.g., /etc/X11/xorg.conf and
PTB-WARNING: /var/log/XOrg.0.log on Linux for hints on what could be misconfigured. This is
PTB-WARNING: very likely not a bug, but a system misconfiguration by you or your distribution vendor.


On 11 December 2016 at 05:04, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


Dear Mario,
Thank you again for the guidance.

Since we are going to use very simple stimuli (black and white gratings) without sound, there is some hope that 240 Hz will work with the configuration you suggested.

If not, do you think we still can use the same 240 Hz monitor at 120Hz mode?

-> You can run it at 1920x1080 240 Hz video mode and just flip your stimuli every 2nd frame, so you get effective 120 fps, e.g., like demonstrated in VBLSyncTest([],2);

My other question is how can we test the timing precision in PTB to be sure that we have truly 240 Hz refresh and that there are no frames missed?

If PTB doesn't complain about timing trouble with error or warning messages - and it shouldn't ever on a properly set up Linux system with the open-source display drivers - then the stimulus onset timestamps returned by Screen('Flip') are very trustworthy and almost micro-second accurate. VBLSyncTest.m shows again how to check for skipped frames and proper timing.

One thing to keep in mind is that the software can only time-stamp what leaves the video output of your computer, not what the actual display is doing. That's why it is often important to run the panel at its native resolution and refresh rate, as various panels do weird things at lower refresh rates, or non-native resolutions.

best,
-mario


Best,
Elena

On 9 December 2016 at 23:11, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:




XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :

Thank you Mario for the detailed information, very useful!

I understand that having good 240 Hz screen refresh may be a challenge.
There are now different monitors on the market that give >120 Hz, e.g. 144 Hz.

What is the highest refresh rate that would stably work in PTB ?

-> That's completely dependent on the quality of the underlying operating system, hence my recommendation for Linux, and the performance and quality of the graphics card and PC hardware. 120 Hz work perfectly reliable on the configuration i told you, i'd assume 144 Hz as well, but i couldn't test that. I'd hope 240 Hz as well, possibly with some tweaking, but without the ability to test that i can't guarantee anything. It obviously also depends on the complexity of your stimuli, if you have to do other things in parallel like sound i/o, keyboard queries, digital i/o etc. - things that take up time in the main stimulation loop, and how efficiently you implement your code.

PTB can stimulate on that Linux setup stably with 1440 Hz, but only with a special - and expensive - Propixx projector and proper coding, so that won't apply to the 240 Hz display you suggested.

You would have to describe what kind of stimuli you intend to present.

What i recommended you gives you a good chance of working, but you may need to come back for tweaking instructions if it doesn't work out of the box. Or you might need an even more high-end card, if you have very complex stimuli. And no guarantees of course.

-mario

Best,
Elena

On 9 December 2016 at 04:39, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


Hello,
I am a beginner and I have probably basic question.
We plan to run motion detection experiment that requires very high time resolution. For this I think to purchase a monitor with the highest available refresh rate (BenQ Zowie XL2540, 4.5" 16:9 1920 x 1080 TN 240Hz ). Will Psychotoolbox be able to handle such a high resolution and what graphic card we would need for that? What operational system (Linux, Mac, Windows) would be preferable?
Any tips would be very valuable!
Elena


-> Hi Elena,


PTB itself can handle that if the underlying OS/hardware can. I strongly recommend Linux, especially for such demanding tasks. But achieving 240 Hz redraw rate consistently without glitches is pushing hard, so even small misconfiguration of the hardware or software, or one sub-standard hardware component in your machine, or slightly suboptimal experiment code could ruin it. I haven't ever run anything at 240 Hz with vsync enabled, as required for proper visual stimulation, due to lack of any suitable displays. In terms of pure graphics performance it isn't a problem for not too complex stimuli, e.g., rendering 1000 fps on average is pretty doable even on on six year old graphics cards. Doing it vsync'ed, with stable refresh and no frame drops is a different issue.


I would recommend a PTB supported/tested Linux distro, e.g., atm. Ubuntu 16.04-LTS or one of its flavors, with a upper end AMD graphics card, using the open-source graphics/display drivers. There are more modern AMD cards available nowadays which should also work, but the most recent card i was able to test with good performance is the AMD Radeon R9 380 "Tonga pro". That one reliably drives a 120 Hz Viewpixx display at 1920x1080 and easily managed simulated 1440 Hz at 960x540 pixels for driving a Propixx projector in its special 12x 120 Hz -> 1440 Hz mode.


The nice thing about Linux with the open-source graphics drivers is that it supports a special mode which allows to use triple-buffering and precise timestamping at the same time, as demonstrated in PerceptualVBLSyncTestFlipInfo2 .m. Thereby you get extra robustness for high framerates due to the triple-buffering, but still trustworthy timestamps for actually checking if your presentation timing was correct during a trial.


However, some tweaking might be required even on Linux with well working hardware, so choice of hardware and software would only be a starting point. Badly configured PC hardware could ruin it even if you basically do everything right. It also depends a lot on the complexity of your stimuli. So this is just a recommendation for a starting point, not a guarantee it will work out of the box, or - if you are unlucky - at all with a specific type of PC hardware or graphics card.


best,

-mario





8
Installing those amdgpu-pro drivers was the mistake. You were supposed to just use the open-source drivers that are installed on your system by default. I knew all previous versions of the amdgpu-pro drivers were faulty wrt. timing. They are very new and still kind of beta quality wrt. more special features like these. I haven't tested the latest ones yet, but you now did and confirmed they are equally broken wrt. timing, so thanks for taking this off my to do list and saving me an hour before christmas :).

I think the drivers come with uninstall instructions or some script you can run to uninstall them. Let's see how it goes without them, and the default drivers instead.

-mario

---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :

Hi Mario,
we purchased a PC with AMD Radeon R9 380 "Tonga pro",  installed  Ubuntu 16.04-LTS and tried to use it with
the 240 Hz display (BenQ Zowie XL2540,  4.5" 16:9 1920 x 1080 TN 240Hz ). We installed the Linux drivers from
Download Not Complete


It seems to fail (as you can see from the text below). Moreover, the refresh rate it gives is only 60 Hz.

It there any way or should we try another monitor?

Elena



PTB-INFO: Display ':0' : X-Screen 0 : Assigning primary output as 0 with RandR-CRTC 0 and GPU-CRTC 0.

PTB-INFO: This is Psychtoolbox-3 for GNU/Linux X11, under Matlab 64-Bit (Version 3.0.12 - Build date: May 13 2016).
PTB-INFO: Support status on this operating system release: Linux 4.4.0-53-lowlatency Supported.
PTB-INFO: Type 'PsychtoolboxVersion' for more detailed version information.
PTB-INFO: Most parts of the Psychtoolbox distribution are licensed to you under terms of the MIT License, with
PTB-INFO: some restrictions. See file 'License.txt' in the Psychtoolbox root folder for the exact licensing conditions.

PTB-INFO: Advanced Micro Devices, Inc. [AMD/ATI] - Tonga PRO [Radeon R9 285/380] GPU found. Trying to establish low-level access...
PTB-INFO: Connected to Advanced Micro Devices, Inc. [AMD/ATI] Tonga PRO [Radeon R9 285/380] GPU with DCE-10.0 display engine [6 heads]. Beamposition timestamping enabled.
PTB-DEBUG:PsychOSGetSwapCompletionTimestamp: Invalid return values ust = 0, msc = 0 from call with success return code (sbc = 20)! Failing with rc = -2.
PTB-DEBUG:PsychOSGetSwapCompletionTimestamp: This likely means a driver bug or malfunction, or that timestamping support has been disabled by the user in the driver!

...

PTB-INFO: OpenGL-Renderer is ATI Technologies Inc. :: AMD Radeon R9 200 Series :: 4.5.13462 Compatibility Profile Context 16.50.5
PTB-INFO: VBL startline = 1080 , VBL Endline = 1123
PTB-INFO: Measured monitor refresh interval from beamposition = 16.667021 ms [59.998726 Hz].
PTB-INFO: Will try to use OS-Builtin OpenML sync control support for accurate Flip timestamping.
PTB-INFO: Measured monitor refresh interval from VBLsync = 16.661187 ms [60.019732 Hz]. (294 valid samples taken, stddev=0.554106 ms.)
PTB-INFO: Reported monitor refresh interval from operating system = 16.666667 ms [60.000000 Hz].
PTB-INFO: Small deviations between reported values are normal and no reason to worry.
PTB-DEBUG:PsychOSGetSwapCompletionTimestamp: Invalid return values ust = 0, msc = 0 from call with success return code (sbc = 305)! Failing with rc = -2.
PTB-DEBUG:PsychOSGetSwapCompletionTimestamp: This likely means a driver bug or malfunction, or that timestamping support has been disabled by the user in the driver!
PTB-WARNING:PsychOSGetSwapCompletionTimestamp() FAILED: errorcode = -2, tSwapComplete = 0.000000.
PTB-WARNING: If this message shows up frequently during sessions, instead of only very sporadically, then
PTB-WARNING: this likely means that timestamping will *not work at all* and has to be considered
PTB-WARNING: not trustworthy! Check your system configuration, e.g., /etc/X11/xorg.conf and
PTB-WARNING: /var/log/XOrg.0.log on Linux for hints on what could be misconfigured. This is
PTB-WARNING: very likely not a bug, but a system misconfiguration by you or your distribution vendor.


On 11 December 2016 at 05:04, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:
 

XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


Dear Mario,
Thank you again for the guidance.

Since we are going to use very simple stimuli  (black and white gratings) without sound, there is some hope that 240 Hz will work with the configuration you suggested.

If not, do you think we still can use the same 240 Hz monitor  at 120Hz mode?

-> You can run it at 1920x1080 240 Hz video mode and just flip your stimuli every 2nd frame, so you get effective 120 fps, e.g., like demonstrated in VBLSyncTest([],2);

My other question is how can we test the  timing precision in PTB to be sure that we have truly 240 Hz refresh and that there are no frames missed?

If PTB doesn't complain about timing trouble with error or warning messages - and it shouldn't ever on a properly set up Linux system with the open-source display drivers - then the stimulus onset timestamps returned by Screen('Flip') are very trustworthy and almost micro-second accurate. VBLSyncTest.m shows again how to check for skipped frames and proper timing.

One thing to keep in mind is that the software can only time-stamp what leaves the video output of your computer, not what the actual display is doing. That's why it is often important to run the panel at its native resolution and refresh rate, as various panels do weird things at lower refresh rates, or non-native resolutions.

best,
-mario


Best,
Elena

On 9 December 2016 at 23:11, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:
 




XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :

Thank you Mario for the detailed information, very useful!

I understand that having good 240 Hz screen refresh may be a challenge.
There are now different monitors on the market  that give >120 Hz, e.g. 144 Hz.

What is the highest refresh rate that would stably work in PTB ?

-> That's completely dependent on the quality of the underlying operating system, hence my recommendation for Linux, and the performance and quality of the graphics card and PC hardware. 120 Hz work perfectly reliable on the configuration i told you, i'd assume 144 Hz as well, but i couldn't test that. I'd hope 240 Hz as well, possibly with some tweaking, but without the ability to test that i can't guarantee anything. It obviously also depends on the complexity of your stimuli, if you have to do other things in parallel like sound i/o, keyboard queries, digital i/o etc. - things that take up time in the main stimulation loop, and how efficiently you implement your code.

PTB can stimulate on that Linux setup stably with 1440 Hz, but only with a special - and expensive - Propixx projector and proper coding, so that won't apply to the 240 Hz display you suggested.

You would have to describe what kind of stimuli you intend to present.

What i recommended you gives you a good chance of working, but you may need to come back for tweaking instructions if it doesn't work out of the box. Or you might need an even more high-end card, if you have very complex stimuli. And no guarantees of course.

-mario

Best,
Elena

On 9 December 2016 at 04:39, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:
 

XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


Hello,
I am a beginner and I have probably basic question.
We plan to run motion detection experiment that requires very high time resolution.  For this I think to purchase a monitor with the highest available refresh rate (BenQ Zowie XL2540,  4.5" 16:9 1920 x 1080 TN 240Hz ).   Will Psychotoolbox be able to handle such a high resolution and what graphic card we would need for that?  What operational system (Linux, Mac, Windows) would be preferable?
Any tips would be very valuable!
Elena


-> Hi Elena,


PTB itself can handle that if the underlying OS/hardware can. I strongly recommend Linux, especially for such demanding tasks. But achieving 240 Hz redraw rate consistently without glitches is pushing hard, so even small misconfiguration of the hardware or software, or one sub-standard hardware component in your machine, or slightly suboptimal experiment code could ruin it. I haven't ever run anything at 240 Hz with vsync enabled, as required for proper visual stimulation, due to lack of any suitable displays. In terms of pure graphics performance it isn't a problem for not too complex stimuli, e.g., rendering 1000 fps on average is pretty doable even on on six year old graphics cards. Doing it vsync'ed, with stable refresh and no frame drops is a different issue.


I would recommend a PTB supported/tested Linux distro, e.g., atm. Ubuntu 16.04-LTS or one of its flavors, with a upper end AMD graphics card, using the open-source graphics/display drivers. There are more modern AMD cards available nowadays which should also work, but the most recent card i was able to test with good performance is the AMD Radeon R9 380 "Tonga pro". That one reliably drives a 120 Hz Viewpixx display at 1920x1080 and easily managed simulated 1440 Hz at 960x540 pixels for driving a Propixx projector in its special 12x 120 Hz -> 1440 Hz mode.


The nice thing about Linux with the open-source graphics drivers is that it supports a special mode which allows to use triple-buffering and precise timestamping at the same time, as demonstrated in PerceptualVBLSyncTestFlipInfo2 .m. Thereby you get extra robustness for high framerates due to the triple-buffering, but still trustworthy timestamps for actually checking if your presentation timing was correct during a trial.


However, some tweaking might be required even on Linux with well working hardware, so choice of hardware and software would only be a starting point. Badly configured PC hardware could ruin it even if you basically do everything right. It also depends a lot on the complexity of your stimuli. So this is just a recommendation for a starting point, not a guarantee it will work out of the box, or - if you are unlucky - at all with a specific type of PC hardware or graphics card.


best,

-mario





9
Oh also to save some time, after doing this, if you don't get the 240 Hz, also post the output of "ResolutionTest", or of the terminal command "xrandr --verbose".

-mario
10
Hi Mario,
Yes, un-installing amdgpu-pro drivers helped! It now works with 144 asn 120 Hz refrash.
It still gives a warning though:
******************************
PTB-INFO: Advanced Micro Devices, Inc. [AMD/ATI] - Tonga PRO [Radeon R9 285/380] GPU found. Trying to establish low-level access...
PTB-INFO: Connected to Advanced Micro Devices, Inc. [AMD/ATI] Tonga PRO [Radeon R9 285/380] GPU with DCE-10.0 display engine [6 heads]. Beamposition timestamping enabled.
PTB-WARNING: At least one test call for OpenML OML_sync_control extension failed! Will disable OpenML and revert to fallback implementation.

PTB-INFO: OpenGL-Renderer is ATI Technologies Inc. :: AMD Radeon R9 200 Series :: 1.4 (4.5.13462 Compatibility Profile Context 16.50.5)
PTB-INFO: VBL startline = 1080 , VBL Endline = 1155
PTB-INFO: Measured monitor refresh interval from beamposition = 6.945411 ms [143.979970 Hz].
PTB-INFO: Will use beamposition query for accurate Flip time stamping.
PTB-INFO: Measured monitor refresh interval from VBLsync = 6.941564 ms [144.059744 Hz]. (570 valid samples taken, stddev=0.321899 ms.)
PTB-INFO: Reported monitor refresh interval from operating system = 6.945409 ms [143.979996 Hz].
PTB-INFO: Small deviations between reported values are normal and no reason to worry.
ifi =0.0069416
*******************************
Is this something serious?


When i do 'xrandr -r 240', I have a problem. Is it fatal and I cannot use 240Hz?? :
******************************
PTB-INFO: Display ':0' : X-Screen 0 : Assigning primary output as 0 with RandR-CRTC 0 and GPU-CRTC 0.

PTB-INFO: This is Psychtoolbox-3 for GNU/Linux X11, under Matlab 64-Bit (Version 3.0.12 - Build date: May 13 2016).
PTB-INFO: Support status on this operating system release: Linux 4.4.0-53-lowlatency Supported.
PTB-INFO: Type 'PsychtoolboxVersion' for more detailed version information.
PTB-INFO: Most parts of the Psychtoolbox distribution are licensed to you under terms of the MIT License, with
PTB-INFO: some restrictions. See file 'License.txt' in the Psychtoolbox root folder for the exact licensing conditions.

PTB-INFO: Advanced Micro Devices, Inc. [AMD/ATI] - Tonga PRO [Radeon R9 285/380] GPU found. Trying to establish low-level access...
PTB-INFO: Connected to Advanced Micro Devices, Inc. [AMD/ATI] Tonga PRO [Radeon R9 285/380] GPU with DCE-10.0 display engine [6 heads]. Beamposition timestamping enabled.
PTB-WARNING: At least one test call for OpenML OML_sync_control extension failed! Will disable OpenML and revert to fallback implementation.

PTB-INFO: OpenGL-Renderer is ATI Technologies Inc. :: AMD Radeon R9 200 Series :: 1.4 (4.5.13462 Compatibility Profile Context 16.50.5)
PTB-INFO: VBL startline = 1080 , VBL Endline = 1213
PTB-INFO: Measured monitor refresh interval from beamposition = 4.170651 ms [239.770702 Hz].
PTB-INFO: Will use beamposition query for accurate Flip time stamping.
PTB-INFO: Measured monitor refresh interval from VBLsync = 4.549026 ms [219.827254 Hz]. (1 valid samples taken, stddev=10000000.000000 ms.)
PTB-INFO: Reported monitor refresh interval from operating system = 4.170855 ms [239.759003 Hz].
PTB-INFO: Small deviations between reported values are normal and no reason to worry.

WARNING: Couldn't compute a reliable estimate of monitor refresh interval! Trouble with VBL syncing?!?

----- ! PTB - ERROR: SYNCHRONIZATION FAILURE ! ----
One or more internal checks (see Warnings above) indicate that synchronization
of Psychtoolbox to the vertical retrace (VBL) is not working on your setup.
...
******************************

Here is the output of 'xrandr --verbose' you asked about:
*******************************
:~$ xrandr --verbose
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
DisplayPort-0 connected primary 1920x1080+0+0 (0x5b) normal (normal left inverted right x axis y axis) 544mm x 303mm
Identifier: 0x55
Timestamp: 2216929
Subpixel: unknown
Gamma: 1.0:1.0:1.0
Brightness: 1.0
Clones:
CRTC: 0
CRTCs: 0 1 2 3 4 5
Transform: 1.000000 0.000000 0.000000
0.000000 1.000000 0.000000
0.000000 0.000000 1.000000
filter:
EDID:
00ffffffffffff0009d1517f45540000
2a1a0104a5361e783f4c00a75552a028
135054a56b80d1c081c081008180a9c0
b30081bc0101023a801871382d40582c
4500202f2100001e000000ff00534147
3032363933534c300a20000000fd0030
f0ffff3c010a202020202020000000fc
005a4f57494520584c204c43440a01ec
020318f14b010203040590111213141f
2309070783010000fe5b80a070383540
30203500202f2100001a866f80a07038
404030203500202f2100001a5a8780a0
70384d4030203500202f2100001a23e8
8078703887401c20980c202f2100001a
9cc700085200a04074903700202f2100
001c000000000000000000000000006b
freesync_capable: 1
range: (0, 1)
freesync: 0
range: (0, 1)
underscan vborder: 0
range: (0, 128)
underscan hborder: 0
range: (0, 128)
underscan: off
supported: off, on, auto
scaling mode: None
supported: None, Full, Center, Full aspect
1920x1080 (0x5a) 148.500MHz +HSync +VSync +preferred
h: width 1920 start 2008 end 2052 total 2200 skew 0 clock 67.50KHz
v: height 1080 start 1084 end 1089 total 1125 clock 60.00Hz
1920x1080 (0x5b) 594.270MHz +HSync -VSync *current
h: width 1920 start 1948 end 1980 total 2040 skew 0 clock 291.31KHz
v: height 1080 start 1137 end 1145 total 1215 clock 239.76Hz
1920x1080 (0x5c) 346.500MHz +HSync -VSync
h: width 1920 start 1968 end 2000 total 2080 skew 0 clock 166.59KHz
v: height 1080 start 1083 end 1088 total 1157 clock 143.98Hz
1920x1080 (0x5d) 285.500MHz +HSync -VSync
h: width 1920 start 1968 end 2000 total 2080 skew 0 clock 137.26KHz
v: height 1080 start 1083 end 1088 total 1144 clock 119.98Hz
1920x1080 (0x5e) 235.500MHz +HSync -VSync
h: width 1920 start 1968 end 2000 total 2080 skew 0 clock 113.22KHz
v: height 1080 start 1083 end 1088 total 1133 clock 99.93Hz
1920x1080 (0x5f) 148.500MHz +HSync +VSync
h: width 1920 start 2448 end 2492 total 2640 skew 0 clock 56.25KHz
v: height 1080 start 1084 end 1089 total 1125 clock 50.00Hz
1920x1080 (0x60) 148.352MHz +HSync +VSync
h: width 1920 start 2008 end 2052 total 2200 skew 0 clock 67.43KHz
v: height 1080 start 1084 end 1089 total 1125 clock 59.94Hz
1680x1050 (0x61) 146.250MHz -HSync +VSync
h: width 1680 start 1784 end 1960 total 2240 skew 0 clock 65.29KHz
v: height 1050 start 1053 end 1059 total 1089 clock 59.95Hz
1600x900 (0x62) 108.000MHz +HSync +VSync
h: width 1600 start 1624 end 1704 total 1800 skew 0 clock 60.00KHz
v: height 900 start 901 end 904 total 1000 clock 60.00Hz
1280x1024 (0x63) 511.000MHz -HSync +VSync
h: width 1280 start 1396 end 1540 total 1800 skew 0 clock 283.89KHz
v: height 1024 start 1027 end 1034 total 1184 clock 239.77Hz
1280x1024 (0x64) 232.250MHz -HSync +VSync
h: width 1280 start 1384 end 1520 total 1760 skew 0 clock 131.96KHz
v: height 1024 start 1027 end 1034 total 1100 clock 119.96Hz
1280x1024 (0x65) 135.000MHz +HSync +VSync
h: width 1280 start 1296 end 1440 total 1688 skew 0 clock 79.98KHz
v: height 1024 start 1025 end 1028 total 1066 clock 75.02Hz
1280x1024 (0x66) 108.000MHz +HSync +VSync
h: width 1280 start 1328 end 1440 total 1688 skew 0 clock 63.98KHz
v: height 1024 start 1025 end 1028 total 1066 clock 60.02Hz
1440x900 (0x67) 148.500MHz +HSync +VSync
h: width 1440 start 2008 end 2052 total 2200 skew 0 clock 67.50KHz
v: height 900 start 1084 end 1089 total 1125 clock 60.00Hz
1280x800 (0x68) 83.500MHz -HSync +VSync
h: width 1280 start 1352 end 1480 total 1680 skew 0 clock 49.70KHz
v: height 800 start 803 end 809 total 831 clock 59.81Hz
1152x864 (0x69) 108.000MHz +HSync +VSync
h: width 1152 start 1216 end 1344 total 1600 skew 0 clock 67.50KHz
v: height 864 start 865 end 868 total 900 clock 75.00Hz
1280x720 (0x6a) 74.250MHz +HSync +VSync
h: width 1280 start 1390 end 1430 total 1650 skew 0 clock 45.00KHz
v: height 720 start 725 end 730 total 750 clock 60.00Hz
1280x720 (0x6b) 74.250MHz +HSync +VSync
h: width 1280 start 1720 end 1760 total 1980 skew 0 clock 37.50KHz
v: height 720 start 725 end 730 total 750 clock 50.00Hz
1280x720 (0x6c) 74.176MHz +HSync +VSync
h: width 1280 start 1390 end 1430 total 1650 skew 0 clock 44.96KHz
v: height 720 start 725 end 730 total 750 clock 59.94Hz
1024x768 (0x6d) 78.800MHz +HSync +VSync
h: width 1024 start 1040 end 1136 total 1312 skew 0 clock 60.06KHz
v: height 768 start 769 end 772 total 800 clock 75.08Hz
1024x768 (0x6e) 65.000MHz -HSync -VSync
h: width 1024 start 1048 end 1184 total 1344 skew 0 clock 48.36KHz
v: height 768 start 771 end 777 total 806 clock 60.00Hz
832x624 (0x6f) 57.284MHz -HSync -VSync
h: width 832 start 864 end 928 total 1152 skew 0 clock 49.73KHz
v: height 624 start 625 end 628 total 667 clock 74.55Hz
800x600 (0x70) 49.500MHz +HSync +VSync
h: width 800 start 816 end 896 total 1056 skew 0 clock 46.88KHz
v: height 600 start 601 end 604 total 625 clock 75.00Hz
800x600 (0x71) 40.000MHz +HSync +VSync
h: width 800 start 840 end 968 total 1056 skew 0 clock 37.88KHz
v: height 600 start 601 end 605 total 628 clock 60.32Hz
720x576 (0x72) 27.000MHz -HSync -VSync
h: width 720 start 732 end 796 total 864 skew 0 clock 31.25KHz
v: height 576 start 581 end 586 total 625 clock 50.00Hz
720x480 (0x73) 27.027MHz -HSync -VSync
h: width 720 start 736 end 798 total 858 skew 0 clock 31.50KHz
v: height 480 start 489 end 495 total 525 clock 60.00Hz
720x480 (0x74) 27.000MHz -HSync -VSync
h: width 720 start 736 end 798 total 858 skew 0 clock 31.47KHz
v: height 480 start 489 end 495 total 525 clock 59.94Hz
640x480 (0x75) 31.500MHz -HSync -VSync
h: width 640 start 656 end 720 total 840 skew 0 clock 37.50KHz
v: height 480 start 481 end 484 total 500 clock 75.00Hz
640x480 (0x76) 25.200MHz -HSync -VSync
h: width 640 start 656 end 752 total 800 skew 0 clock 31.50KHz
v: height 480 start 490 end 492 total 525 clock 60.00Hz
640x480 (0x77) 25.175MHz -HSync -VSync
h: width 640 start 656 end 752 total 800 skew 0 clock 31.47KHz
v: height 480 start 490 end 492 total 525 clock 59.94Hz
720x400 (0x78) 28.320MHz -HSync +VSync
h: width 720 start 738 end 846 total 900 skew 0 clock 31.47KHz
v: height 400 start 412 end 414 total 449 clock 70.08Hz
HDMI-A-0 disconnected (normal left inverted right x axis y axis)
Identifier: 0x56
Timestamp: 2216929
Subpixel: unknown
Clones:
CRTCs: 0 1 2 3 4 5
Transform: 1.000000 0.000000 0.000000
0.000000 1.000000 0.000000
0.000000 0.000000 1.000000
filter:
freesync_capable: 0
range: (0, 1)
freesync: 0
range: (0, 1)
underscan vborder: 0
range: (0, 128)
underscan hborder: 0
range: (0, 128)
underscan: off
supported: off, on, auto
scaling mode: None
supported: None, Full, Center, Full aspect
DVI-D-0 disconnected (normal left inverted right x axis y axis)
Identifier: 0x57
Timestamp: 2216929
Subpixel: unknown
Clones:
CRTCs: 0 1 2 3 4 5
Transform: 1.000000 0.000000 0.000000
0.000000 1.000000 0.000000
0.000000 0.000000 1.000000
filter:
underscan vborder: 0
range: (0, 128)
underscan hborder: 0
range: (0, 128)
underscan: off
supported: off, on, auto
scaling mode: None
supported: None, Full, Center, Full aspect
DVI-D-1 disconnected (normal left inverted right x axis y axis)
Identifier: 0x58
Timestamp: 2216929
Subpixel: unknown
Clones:
CRTCs: 0 1 2 3 4 5
Transform: 1.000000 0.000000 0.000000
0.000000 1.000000 0.000000
0.000000 0.000000 1.000000
filter:
underscan vborder: 0
range: (0, 128)
underscan hborder: 0
range: (0, 128)
underscan: off
supported: off, on, auto
scaling mode: None
supported: None, Full, Center, Full aspect

******************************

Elena

On 16 December 2016 at 06:56, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

Oh also to save some time, after doing this, if you don't get the 240 Hz, also post the output of "ResolutionTest", or of the terminal command "xrandr --verbose".

-mario


11
Not sure what happened on your side, but the driver is not properly uninstalled or not uninstalled at all, otherwise it wouldn't say "OpenGL-Renderer is ATI Technologies Inc. :: AMD Radeon R9 200 Series ::" but something like "X.Org :: Gallium 0.4 on AMD Tonga" in that place. That's also the reason for those error messages. Other than that you managed at least to switch the display to 240 Hz mode, so that's a good step forward.

Can your try again, checking the instructions for uninstallation carefully?
-mario
12
Indeed, after removing the drivers i have now "X.Org :: Gallium 0.4 on AMD Tonga...'
message. PTB does not generate the errors any more. However, I now have another problem, that I have not had with the amdgpu-pro driver: the right side of the screen (about 1/4 of the screen) is a kind of smeared and trembles. It seems that the generic driver does not fully support 240Hz. On the other hand, I only use the central part of the screen for presentation and the trembling is not seen on the gray background. Is it still unsafe to use 240 Hz refresh mode in this situation?

Elena

On 17 December 2016 at 07:27, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

Not sure what happened on your side, but the driver is not properly uninstalled or not uninstalled at all, otherwise it wouldn't say "OpenGL-Renderer is ATI Technologies Inc. :: AMD Radeon R9 200 Series ::" but something like "X.Org :: Gallium 0.4 on AMD Tonga" in that place. That's also the reason for those error messages. Other than that you managed at least to switch the display to 240 Hz mode, so that's a good step forward.

Can your try again, checking the instructions for uninstallation carefully?
-mario


13
XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :

Indeed, after removing the drivers i have now "X.Org :: Gallium 0.4 on AMD Tonga...'
message. PTB  does not generate the errors any more. However, I now have another problem, that I have not had with the amdgpu-pro driver: the right side of the screen (about 1/4 of the screen) is a kind of smeared and trembles. It seems that  the generic driver  does not fully support 240Hz. On the other hand,  I only use the central part of the screen for presentation and the trembling is not seen on the gray background. Is it still unsafe to use 240 Hz refresh mode in this situation?

-> Ok, so the timing and timestamping should be solid if PTB doesn't print any warnings or errors anymore, but that trembling/smear (photo/video would be interesting to judge how those artifacts look) is not nice at all of course. Probably the display controller doesn't get enough memory bandwidth for the fast 240 Hz and the line buffer fifos underflow.

-> Can you post the full output and possibly figures of a run of VBLSyncTest?

We can try to force the driver into choosing a higher performance level, using faster memory clocks, maybe that helps. Try this from a terminal and see if it helps:

1. sudo su
2. Enter admin password.
3. echo performance > /sys/class/drm/card0/device/power_dpm_state

If step 3 doesn't help, try this:

4. echo high > /sys/class/drm/card0/device/power_dpm_force_performance_level

Any change?

You should run VBLSyncTest, and PerceptualVBLSyncTest to see if they show expected results and if the systm is capable of presenting at 240 fps without dropping frames. Timing-wise it should be safe to use the system at 240 Hz even with the artifacts, if you are certain they don't extend into the display area where you actually show your stimuli. But lets see if we can fix this.

-mario

Elena

On 17 December 2016 at 07:27, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:
 

Not sure what happened on your side, but the driver is not properly uninstalled or not uninstalled at all, otherwise it wouldn't say "OpenGL-Renderer is ATI Technologies Inc. :: AMD Radeon R9 200 Series ::" but something like "X.Org :: Gallium 0.4 on AMD Tonga" in that place. That's also the reason for those error messages. Other than that you managed at least to switch the display to 240 Hz mode, so that's a good step forward.

Can your try again, checking the instructions for uninstallation carefully?
-mario


14
>1. sudo su
>2. Enter admin password.
>3. echo performance > /sys/class/drm/card0/device/ power_dpm_state

>If step 3 doesn't help, try this:

>4. echo high > /sys/class/drm/card0/device/ power_dpm_force_performance_ level

>Any change?

I have done steps 1-3, relaunched the terminal window/matlab, but have not noticed any changes in the display.
Then I have done the step 4 and rebooted the computer.
After the reboot I had a strange pattern on the screen for 3 seconds and then an empty blue screen forever.
It seems that I spoiled something...

Elena



On 20 December 2016 at 10:19, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


Indeed, after removing the drivers i have now "X.Org :: Gallium 0.4 on AMD Tonga...'
message. PTB does not generate the errors any more. However, I now have another problem, that I have not had with the amdgpu-pro driver: the right side of the screen (about 1/4 of the screen) is a kind of smeared and trembles. It seems that the generic driver does not fully support 240Hz. On the other hand, I only use the central part of the screen for presentation and the trembling is not seen on the gray background. Is it still unsafe to use 240 Hz refresh mode in this situation?

-> Ok, so the timing and timestamping should be solid if PTB doesn't print any warnings or errors anymore, but that trembling/smear (photo/video would be interesting to judge how those artifacts look) is not nice at all of course. Probably the display controller doesn't get enough memory bandwidth for the fast 240 Hz and the line buffer fifos underflow.

-> Can you post the full output and possibly figures of a run of VBLSyncTest?

We can try to force the driver into choosing a higher performance level, using faster memory clocks, maybe that helps. Try this from a terminal and see if it helps:

1. sudo su
2. Enter admin password.
3. echo performance > /sys/class/drm/card0/device/ power_dpm_state

If step 3 doesn't help, try this:

4. echo high > /sys/class/drm/card0/device/ power_dpm_force_performance_ level

Any change?

You should run VBLSyncTest, and PerceptualVBLSyncTest to see if they show expected results and if the systm is capable of presenting at 240 fps without dropping frames. Timing-wise it should be safe to use the system at 240 Hz even with the artifacts, if you are certain they don't extend into the display area where you actually show your stimuli. But lets see if we can fix this.

-mario

Elena

On 17 December 2016 at 07:27, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

Not sure what happened on your side, but the driver is not properly uninstalled or not uninstalled at all, otherwise it wouldn't say "OpenGL-Renderer is ATI Technologies Inc. :: AMD Radeon R9 200 Series ::" but something like "X.Org :: Gallium 0.4 on AMD Tonga" in that place. That's also the reason for those error messages. Other than that you managed at least to switch the display to 240 Hz mode, so that's a good step forward.

Can your try again, checking the instructions for uninstallation carefully?
-mario



15
XX-In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :

>1. sudo su
>2. Enter admin password.
>3. echo performance > /sys/class/drm/card0/device/ power_dpm_state

>If step 3 doesn't help, try this:

>4. echo high > /sys/class/drm/card0/device/ power_dpm_force_performance_ level

>Any change?

I have done steps 1-3, relaunched the terminal window/matlab, but have not noticed any changes in the display.
Then I have done the step 4 and rebooted the computer.

-> So no improvement, and also not any error message in response to your commands?

After the reboot I had a strange pattern on the screen for 3 seconds and then an empty blue screen forever.
It seems that I spoiled something...

-> You can't have spoiled something, at least not with those commands. Those settings are not persistent over a reboot. They apply immediately and get reset to defaults when the machine restarts. When exactly did the screen turn blue? Did it make it to the login window and only turned blue then? Or already before? If you press CTRL + F1, do you get a proper text console? Does it happen on each reboot? What happens if you connect a different monitor?

-mario



Elena



On 20 December 2016 at 10:19, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:
 

XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


Indeed, after removing the drivers i have now "X.Org :: Gallium 0.4 on AMD Tonga...'
message. PTB  does not generate the errors any more. However, I now have another problem, that I have not had with the amdgpu-pro driver: the right side of the screen (about 1/4 of the screen) is a kind of smeared and trembles. It seems that  the generic driver  does not fully support 240Hz. On the other hand,  I only use the central part of the screen for presentation and the trembling is not seen on the gray background. Is it still unsafe to use 240 Hz refresh mode in this situation?

-> Ok, so the timing and timestamping should be solid if PTB doesn't print any warnings or errors anymore, but that trembling/smear (photo/video would be interesting to judge how those artifacts look) is not nice at all of course. Probably the display controller doesn't get enough memory bandwidth for the fast 240 Hz and the line buffer fifos underflow.

-> Can you post the full output and possibly figures of a run of VBLSyncTest?

We can try to force the driver into choosing a higher performance level, using faster memory clocks, maybe that helps. Try this from a terminal and see if it helps:

1. sudo su
2. Enter admin password.
3. echo performance > /sys/class/drm/card0/device/ power_dpm_state

If step 3 doesn't help, try this:

4. echo high > /sys/class/drm/card0/device/ power_dpm_force_performance_ level

Any change?

You should run VBLSyncTest, and PerceptualVBLSyncTest to see if they show expected results and if the systm is capable of presenting at 240 fps without dropping frames. Timing-wise it should be safe to use the system at 240 Hz even with the artifacts, if you are certain they don't extend into the display area where you actually show your stimuli. But lets see if we can fix this.

-mario

Elena

On 17 December 2016 at 07:27, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:
 

Not sure what happened on your side, but the driver is not properly uninstalled or not uninstalled at all, otherwise it wouldn't say "OpenGL-Renderer is ATI Technologies Inc. :: AMD Radeon R9 200 Series ::" but something like "X.Org :: Gallium 0.4 on AMD Tonga" in that place. That's also the reason for those error messages. Other than that you managed at least to switch the display to 240 Hz mode, so that's a good step forward.

Can your try again, checking the instructions for uninstallation carefully?
-mario



16
>-> So no improvement, and also not any error message in response to your commands?
No, I still had the same trembling in the right 1/4 of the screen.

>After the reboot I had a strange pattern on the screen for 3 seconds and then an empty blue screen forever.
>It seems that I spoiled something...
>->
You can't have spoiled something, at least not with those commands. Those settings are not persistent over a >reboot. They apply immediately and get reset to defaults when the machine restarts. When exactly did the screen >turn >blue?
>Did it make it to the login window and only turned
blue then? Or already before? If you press CTRL + F1, do you >get a >proper text console?
After I login to Ubuntu with my password the screen first looks checkered, then after 3 seconds it is blue.
After I did F1 it still looks blue (not native ubuntu color), but at least I can see the icons. However, I do not have my files on the desktop.

Does it happen on each reboot?
Yes

What happens if you connect a different monitor?
Did not try this yet. I will send you the PTB VBLSyncTest report and figures (attached) first, then try ...

Elena

************************
VBLSyncTest

ans =
t
0

PTB-INFO: This is Psychtoolbox-3 for GNU/Linux X11, under Matlab 64-Bit (Version 3.0.12 - Build date: May 13 2016).
PTB-INFO: Support status on this operating system release: Linux 4.4.0-53-generic Supported.
PTB-INFO: Type 'PsychtoolboxVersion' for more detailed version information.
PTB-INFO: Most parts of the Psychtoolbox distribution are licensed to you under terms of the MIT License, with
PTB-INFO: some restrictions. See file 'License.txt' in the Psychtoolbox root folder for the exact licensing conditions.

PTB-INFO: Advanced Micro Devices, Inc. [AMD/ATI] - Tonga PRO [Radeon R9 285/380] GPU found. Trying to establish low-level access...
PTB-INFO: Connected to Advanced Micro Devices, Inc. [AMD/ATI] Tonga PRO [Radeon R9 285/380] GPU with DCE-10.0 display engine [6 heads]. Beamposition timestamping enabled.


PTB-INFO: OpenGL-Renderer is X.Org :: Gallium 0.4 on AMD TONGA (DRM 3.1.0, LLVM 3.8.0) :: 3.0 Mesa 11.2.0
PTB-INFO: VBL startline = 1080 , VBL Endline = 1213
PTB-INFO: Measured monitor refresh interval from beamposition = 4.308817 ms [232.082245 Hz].
PTB-INFO: Will try to use OS-Builtin OpenML sync control support for accurate Flip timestamping.
PTB-INFO: Measured monitor refresh interval from VBLsync = 4.308863 ms [232.079802 Hz]. (50 valid samples taken, stddev=0.002586 ms.)
PTB-INFO: Reported monitor refresh interval from operating system = 4.170855 ms [239.759003 Hz].
PTB-INFO: Small deviations between reported values are normal and no reason to worry.
The refresh interval reported by the operating system is 4.16667 ms.
Measured refresh interval, as reported by "GetFlipInterval" is 4.30886 ms. (nsamples = 0, stddev = 0.00000 ms)

ans =

1

PTB missed 1 out of 600 stimulus presentation deadlines.
One missed deadline is ok and an artifact of the measurement.
PTB completed 0 stimulus presentations before the requested target time.
Have a look at the plots for more details...
*********************************************



On 21 December 2016 at 03:05, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

XX-In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


>1. sudo su
>2. Enter admin password.
>3. echo performance > /sys/class/drm/card0/device/ power_dpm_state

>If step 3 doesn't help, try this:

>4. echo high > /sys/class/drm/card0/device/ power_dpm_force_performance_ level

>Any change?

I have done steps 1-3, relaunched the terminal window/matlab, but have not noticed any changes in the display.
Then I have done the step 4 and rebooted the computer.

-> So no improvement, and also not any error message in response to your commands?

After the reboot I had a strange pattern on the screen for 3 seconds and then an empty blue screen forever.
It seems that I spoiled something...

-> You can't have spoiled something, at least not with those commands. Those settings are not persistent over a reboot. They apply immediately and get reset to defaults when the machine restarts. When exactly did the screen turn blue? Did it make it to the login window and only turned blue then? Or already before? If you press CTRL + F1, do you get a proper text console? Does it happen on each reboot? What happens if you connect a different monitor?

-mario



Elena



On 20 December 2016 at 10:19, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


Indeed, after removing the drivers i have now "X.Org :: Gallium 0.4 on AMD Tonga...'
message. PTB does not generate the errors any more. However, I now have another problem, that I have not had with the amdgpu-pro driver: the right side of the screen (about 1/4 of the screen) is a kind of smeared and trembles. It seems that the generic driver does not fully support 240Hz. On the other hand, I only use the central part of the screen for presentation and the trembling is not seen on the gray background. Is it still unsafe to use 240 Hz refresh mode in this situation?

-> Ok, so the timing and timestamping should be solid if PTB doesn't print any warnings or errors anymore, but that trembling/smear (photo/video would be interesting to judge how those artifacts look) is not nice at all of course. Probably the display controller doesn't get enough memory bandwidth for the fast 240 Hz and the line buffer fifos underflow.

-> Can you post the full output and possibly figures of a run of VBLSyncTest?

We can try to force the driver into choosing a higher performance level, using faster memory clocks, maybe that helps. Try this from a terminal and see if it helps:

1. sudo su
2. Enter admin password.
3. echo performance > /sys/class/drm/card0/device/ power_dpm_state

If step 3 doesn't help, try this:

4. echo high > /sys/class/drm/card0/device/ power_dpm_force_performance_ level

Any change?

You should run VBLSyncTest, and PerceptualVBLSyncTest to see if they show expected results and if the systm is capable of presenting at 240 fps without dropping frames. Timing-wise it should be safe to use the system at 240 Hz even with the artifacts, if you are certain they don't extend into the display area where you actually show your stimuli. But lets see if we can fix this.

-mario

Elena

On 17 December 2016 at 07:27, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

Not sure what happened on your side, but the driver is not properly uninstalled or not uninstalled at all, otherwise it wouldn't say "OpenGL-Renderer is ATI Technologies Inc. :: AMD Radeon R9 200 Series ::" but something like "X.Org :: Gallium 0.4 on AMD Tonga" in that place. That's also the reason for those error messages. Other than that you managed at least to switch the display to 240 Hz mode, so that's a good step forward.

Can your try again, checking the instructions for uninstallation carefully?
-mario




17
Hi Mario,
just to update,...
after CTRL + F1 and rebooting I have now a normal ubuntu display. So, no worries.

However,
echo performance > /sys/class/drm/card0/device/ power_dpm_state
echo high > /sys/class/drm/card0/device/ power_dpm_force_performance_ level
commands have not had any positive effect on the 240 Hz display. I still have the same trembling/smearing on 1/4th part if the screen.
At the same time, PTB does not complain and when I run PerceptualVBLSyncTest, the yellow lines are concentrated on the top of the screen.

Elena


*****************************
PerceptualVBLSyncTest

Press ENTER key to start the test. The test will stop after 10 seconds
or any keypress...


PTB-INFO: This is Psychtoolbox-3 for GNU/Linux X11, under Matlab 64-Bit (Version 3.0.12 - Build date: May 13 2016).
PTB-INFO: Support status on this operating system release: Linux 4.4.0-53-generic Supported.
PTB-INFO: Type 'PsychtoolboxVersion' for more detailed version information.
PTB-INFO: Most parts of the Psychtoolbox distribution are licensed to you under terms of the MIT License, with
PTB-INFO: some restrictions. See file 'License.txt' in the Psychtoolbox root folder for the exact licensing conditions.

PTB-INFO: Advanced Micro Devices, Inc. [AMD/ATI] - Tonga PRO [Radeon R9 285/380] GPU found. Trying to establish low-level access...
PTB-INFO: Connected to Advanced Micro Devices, Inc. [AMD/ATI] Tonga PRO [Radeon R9 285/380] GPU with DCE-10.0 display engine [6 heads]. Beamposition timestamping enabled.


PTB-INFO: OpenGL-Renderer is X.Org :: Gallium 0.4 on AMD TONGA (DRM 3.1.0, LLVM 3.8.0) :: 3.0 Mesa 11.2.0
PTB-INFO: VBL startline = 1080 , VBL Endline = 1213
PTB-INFO: Measured monitor refresh interval from beamposition = 4.308817 ms [232.082245 Hz].
PTB-INFO: Will try to use OS-Builtin OpenML sync control support for accurate Flip timestamping.
PTB-INFO: Measured monitor refresh interval from VBLsync = 4.308782 ms [232.084168 Hz]. (50 valid samples taken, stddev=0.003222 ms.)
PTB-INFO: Reported monitor refresh interval from operating system = 4.170855 ms [239.759003 Hz].
PTB-INFO: Small deviations between reported values are normal and no reason to worry.
>>



On 21 December 2016 at 03:05, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

XX-In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


>1. sudo su
>2. Enter admin password.
>3. echo performance > /sys/class/drm/card0/device/ power_dpm_state

>If step 3 doesn't help, try this:

>4. echo high > /sys/class/drm/card0/device/ power_dpm_force_performance_ level

>Any change?

I have done steps 1-3, relaunched the terminal window/matlab, but have not noticed any changes in the display.
Then I have done the step 4 and rebooted the computer.

-> So no improvement, and also not any error message in response to your commands?

After the reboot I had a strange pattern on the screen for 3 seconds and then an empty blue screen forever.
It seems that I spoiled something...

-> You can't have spoiled something, at least not with those commands. Those settings are not persistent over a reboot. They apply immediately and get reset to defaults when the machine restarts. When exactly did the screen turn blue? Did it make it to the login window and only turned blue then? Or already before? If you press CTRL + F1, do you get a proper text console? Does it happen on each reboot? What happens if you connect a different monitor?

-mario



Elena



On 20 December 2016 at 10:19, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


Indeed, after removing the drivers i have now "X.Org :: Gallium 0.4 on AMD Tonga...'
message. PTB does not generate the errors any more. However, I now have another problem, that I have not had with the amdgpu-pro driver: the right side of the screen (about 1/4 of the screen) is a kind of smeared and trembles. It seems that the generic driver does not fully support 240Hz. On the other hand, I only use the central part of the screen for presentation and the trembling is not seen on the gray background. Is it still unsafe to use 240 Hz refresh mode in this situation?

-> Ok, so the timing and timestamping should be solid if PTB doesn't print any warnings or errors anymore, but that trembling/smear (photo/video would be interesting to judge how those artifacts look) is not nice at all of course. Probably the display controller doesn't get enough memory bandwidth for the fast 240 Hz and the line buffer fifos underflow.

-> Can you post the full output and possibly figures of a run of VBLSyncTest?

We can try to force the driver into choosing a higher performance level, using faster memory clocks, maybe that helps. Try this from a terminal and see if it helps:

1. sudo su
2. Enter admin password.
3. echo performance > /sys/class/drm/card0/device/ power_dpm_state

If step 3 doesn't help, try this:

4. echo high > /sys/class/drm/card0/device/ power_dpm_force_performance_ level

Any change?

You should run VBLSyncTest, and PerceptualVBLSyncTest to see if they show expected results and if the systm is capable of presenting at 240 fps without dropping frames. Timing-wise it should be safe to use the system at 240 Hz even with the artifacts, if you are certain they don't extend into the display area where you actually show your stimuli. But lets see if we can fix this.

-mario

Elena

On 17 December 2016 at 07:27, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

Not sure what happened on your side, but the driver is not properly uninstalled or not uninstalled at all, otherwise it wouldn't say "OpenGL-Renderer is ATI Technologies Inc. :: AMD Radeon R9 200 Series ::" but something like "X.Org :: Gallium 0.4 on AMD Tonga" in that place. That's also the reason for those error messages. Other than that you managed at least to switch the display to 240 Hz mode, so that's a good step forward.

Can your try again, checking the instructions for uninstallation carefully?
-mario




18
Hi Mario,
>->
Ok, good. However, i wonder how stable that is, and if it can't come back under certain conditions? The trembling >you describe and that "blue screen" are likely related.
Now it looks normal after reboot, no blue screen any more. I do not know why, but I run some ubuntu updated. Possibly it had a role. Anyway, the screen again looks fine at <240 Hz.

>It could be that on average load on the
memory you get >trembling, but if there is some spike in memory bandwidth >demand, the display controller doesn't get enough date for even the leftmost 3/4 of the display and malfunctions harder >and that causes that "blue screen". It's quite unclear to me how these things look. Could you create some photos or a >short video of it somewhere?
The trembling occurs irrespective of blue or normal screen. When i do 'xrands -r 240 ' thr trembling is there. I attached a photo. (Note that you can't read the text on the left side - my right).



>->
What confuses me here in your post is that single blank space between /sys/class/drm/card0/device/ and the >power_dpm_state and power_dpm_force_performance_ level? Is this a copy & paste / formatting error or did you really >have a blank space there? In that case the commands would have failed and done nothing except maybe print some >error message?
I removed the empty spaces, and I have not had any error while running the commands.

>If you apply above commands, what is the output of:
>cat
/sys/class/drm/card0/device/ power_dpm_state
 performance

>and
>cat /sys/class/drm/card0/device/ power_dpm_force_performance_ level
auto

>Also
the full output of the command dmesg would be interesting to see if the driver reports back any errors during >switching of video refresh rate to 60 Hz and back to 240 Hz:
sudo su
>echo 4 > /sys/module/drm/parameters/ debug
>xrandr -r 60
>xrandr -r 240
>dmesg > dmesg_log.txt
>Creates a text file dmesg_log.txt with that output in the current directory.
I performed these operations and attached the dmesg_log.txt file

>->
Another thing you could try is upgrading to the latest version of the Linux kernel, in the hope that the 240 Hz problem >doesn't exist in the latest drivers anymore, if you are interested in that?
Do you meen upgrating to another Ubuntu version?
I've already done : sudo apt-get dist-upgrade

>-> Another thing you could try is keeping the 240 Hz refresh rate, but reduce the display resolution to >1280x1024 if that is sufficient for your purpose, as according to one of your previous posts, that video >resolution also supports 240 Hz and maybe the driver handles that better?
Yes, indeed, there is no trembling any more with these settings. Possibly, I can use this screen size.

Thanks!
Elena

On 22 December 2016 at 07:57, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


Hi Mario,
just to update,...
after CTRL + F1 and rebooting I have now a normal ubuntu display. So, no worries.

-> Ok, good. However, i wonder how stable that is, and if it can't come back under certain conditions? The trembling you describe and that "blue screen" are likely related. It could be that on average load on the memory you get trembling, but if there is some spike in memory bandwidth demand, the display controller doesn't get enough date for even the leftmost 3/4 of the display and malfunctions harder and that causes that "blue screen". It's quite unclear to me how these things look. Could you create some photos or a short video of it somewhere?

My suspicion why you got that after a reboot would be that the desktop GUI remembered that you prefer the display running at 240 Hz, ie. it stored that setting in a configuration file. Then during login, the desktop GUI switched the display from the default mode of 60 Hz back to 240 Hz.

If this happens again, and you can't easily recover from it, one way to recover is to press CTRL+ALT+F1 for a text console (sorry, i gave you the wrong key combo, it is not CTRL+F1 but CTRL+ALT+F1), login at the text console, and then type:

rm ~/.config/monitors.xml

to delete the file with the display default video settings. Then go back to the GUI with CTRL+ALT+F7 and login normally. That should start the desktop GUI at a safe default video mode for your display of 60 Hz instead of 240 Hz, after the GUI has forgotten your preferred setting.


However,
echo performance > /sys/class/drm/card0/device/ power_dpm_state
echo high > /sys/class/drm/card0/device/ power_dpm_force_performance_ level
commands have not had any positive effect on the 240 Hz display. I still have the same trembling/smearing on 1/4th part if the screen.

-> What confuses me here in your post is that single blank space between /sys/class/drm/card0/device/ and the power_dpm_state and power_dpm_force_performance_ level? Is this a copy & paste / formatting error or did you really have a blank space there? In that case the commands would have failed and done nothing except maybe print some error message?

If you apply above commands, what is the output of:

cat /sys/class/drm/card0/device/ power_dpm_state

and

cat /sys/class/drm/card0/device/ power_dpm_force_performance_ level

Also the full output of the command dmesg would be interesting to see if the driver reports back any errors during switching of video refresh rate to 60 Hz and back to 240 Hz:

echo 4 > /sys/module/drm/parameters/ debug
xrandr -r 60
xrandr -r 240
dmesg > dmesg_log.txt

Creates a text file dmesg_log.txt with that output in the current directory.


At the same time, PTB does not complain and when I run PerceptualVBLSyncTest, the yellow lines are concentrated on the top of the screen.

-> Apart from that smeared right 1/4 of your screen, the output of PTB you posted and the figures look perfect. Everything else seems to work optimally and at least our VBLSyncTest apparently works without dropping any frames at 240 Hz. So if that would work for your experiment script as well, you should be good. If not, there are various ways to tweak the script.

-> Another thing you could try is upgrading to the latest version of the Linux kernel, in the hope that the 240 Hz problem doesn't exist in the latest drivers anymore, if you are interested in that?

-> Another thing you could try is keeping the 240 Hz refresh rate, but reduce the display resolution to 1280x1024 if that is sufficient for your purpose, as according to one of your previous posts, that video resolution also supports 240 Hz and maybe the driver handles that better?

From within PTB scripts you can use SetResolution() to change resolution and refresh rate as long as only one display is connected, e.g.,

oldres = SetResolution (0, 1280, 1024, 240);

to set 1280x1024 at 240 Hz, and

SetResolution(0, oldres);

to restore the previous video settings.

-mario



Elena


*****************************
PerceptualVBLSyncTest

Press ENTER key to start the test. The test will stop after 10 seconds
or any keypress...


PTB-INFO: This is Psychtoolbox-3 for GNU/Linux X11, under Matlab 64-Bit (Version 3.0.12 - Build date: May 13 2016).
PTB-INFO: Support status on this operating system release: Linux 4.4.0-53-generic Supported.
PTB-INFO: Type 'PsychtoolboxVersion' for more detailed version information.
PTB-INFO: Most parts of the Psychtoolbox distribution are licensed to you under terms of the MIT License, with
PTB-INFO: some restrictions. See file 'License.txt' in the Psychtoolbox root folder for the exact licensing conditions.

PTB-INFO: Advanced Micro Devices, Inc. [AMD/ATI] - Tonga PRO [Radeon R9 285/380] GPU found. Trying to establish low-level access...
PTB-INFO: Connected to Advanced Micro Devices, Inc. [AMD/ATI] Tonga PRO [Radeon R9 285/380] GPU with DCE-10.0 display engine [6 heads]. Beamposition timestamping enabled.


PTB-INFO: OpenGL-Renderer is X.Org :: Gallium 0.4 on AMD TONGA (DRM 3.1.0, LLVM 3.8.0) :: 3.0 Mesa 11.2.0
PTB-INFO: VBL startline = 1080 , VBL Endline = 1213
PTB-INFO: Measured monitor refresh interval from beamposition = 4.308817 ms [232.082245 Hz].
PTB-INFO: Will try to use OS-Builtin OpenML sync control support for accurate Flip timestamping.
PTB-INFO: Measured monitor refresh interval from VBLsync = 4.308782 ms [232.084168 Hz]. (50 valid samples taken, stddev=0.003222 ms.)
PTB-INFO: Reported monitor refresh interval from operating system = 4.170855 ms [239.759003 Hz].
PTB-INFO: Small deviations between reported values are normal and no reason to worry.
>>



On 21 December 2016 at 03:05, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

XX-In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


>1. sudo su
>2. Enter admin password.
>3. echo performance > /sys/class/drm/card0/device/ power_dpm_state

>If step 3 doesn't help, try this:

>4. echo high > /sys/class/drm/card0/device/ power_dpm_force_performance_ level

>Any change?

I have done steps 1-3, relaunched the terminal window/matlab, but have not noticed any changes in the display.
Then I have done the step 4 and rebooted the computer.

-> So no improvement, and also not any error message in response to your commands?

After the reboot I had a strange pattern on the screen for 3 seconds and then an empty blue screen forever.
It seems that I spoiled something...

-> You can't have spoiled something, at least not with those commands. Those settings are not persistent over a reboot. They apply immediately and get reset to defaults when the machine restarts. When exactly did the screen turn blue? Did it make it to the login window and only turned blue then? Or already before? If you press CTRL + F1, do you get a proper text console? Does it happen on each reboot? What happens if you connect a different monitor?

-mario



Elena



On 20 December 2016 at 10:19, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


Indeed, after removing the drivers i have now "X.Org :: Gallium 0.4 on AMD Tonga...'
message. PTB does not generate the errors any more. However, I now have another problem, that I have not had with the amdgpu-pro driver: the right side of the screen (about 1/4 of the screen) is a kind of smeared and trembles. It seems that the generic driver does not fully support 240Hz. On the other hand, I only use the central part of the screen for presentation and the trembling is not seen on the gray background. Is it still unsafe to use 240 Hz refresh mode in this situation?

-> Ok, so the timing and timestamping should be solid if PTB doesn't print any warnings or errors anymore, but that trembling/smear (photo/video would be interesting to judge how those artifacts look) is not nice at all of course. Probably the display controller doesn't get enough memory bandwidth for the fast 240 Hz and the line buffer fifos underflow.

-> Can you post the full output and possibly figures of a run of VBLSyncTest?

We can try to force the driver into choosing a higher performance level, using faster memory clocks, maybe that helps. Try this from a terminal and see if it helps:

1. sudo su
2. Enter admin password.
3. echo performance > /sys/class/drm/card0/device/ power_dpm_state

If step 3 doesn't help, try this:

4. echo high > /sys/class/drm/card0/device/ power_dpm_force_performance_ level

Any change?

You should run VBLSyncTest, and PerceptualVBLSyncTest to see if they show expected results and if the systm is capable of presenting at 240 fps without dropping frames. Timing-wise it should be safe to use the system at 240 Hz even with the artifacts, if you are certain they don't extend into the display area where you actually show your stimuli. But lets see if we can fix this.

-mario

Elena

On 17 December 2016 at 07:27, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

Not sure what happened on your side, but the driver is not properly uninstalled or not uninstalled at all, otherwise it wouldn't say "OpenGL-Renderer is ATI Technologies Inc. :: AMD Radeon R9 200 Series ::" but something like "X.Org :: Gallium 0.4 on AMD Tonga" in that place. That's also the reason for those error messages. Other than that you managed at least to switch the display to 240 Hz mode, so that's a good step forward.

Can your try again, checking the instructions for uninstallation carefully?
-mario





19
XXX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :

Hi Mario,

...

The trembling occurs irrespective of blue or normal screen. When i do  'xrands -r 240 ' thr trembling is there. I attached a photo. (Note that you can't read the text on the left side - my right).


=> Ok, thanks. That photo looks different from what i would have expected. Maybe because it's a photo and not a movie, so one doesn't see the trembling. Or maybe because my suspicion about the cause of the trembling is wrong, and something else goes wrong with signal transmission. Seems to be more the rightmost 1/5th of the display? Why ist the photo left-right flipped?

I removed the empty spaces, and I have not had any error while running the commands.

cat /sys/class/drm/card0/device/power_dpm_state
   performance

>and
>cat /sys/class/drm/card0/device/ power_dpm_force_performance_ level
   auto

=> Looks correct.

the full output of the command dmesg would be interesting to see if the driver reports back any errors during >switching of video refresh rate to 60 Hz and back to 240 Hz:
sudo su
>echo 4 > /sys/module/drm/parameters/ debug
>xrandr -r 60
>xrandr -r 240
>dmesg > dmesg_log.txt
>Creates a text file dmesg_log.txt with that output in the current directory.
 I performed these operations and attached the  dmesg_log.txt file

=> Thanks. Doesn't show anything suspicious, but captures useful debug info.

Another thing you could try is upgrading to the latest version of the Linux kernel, in the hope that the 240 Hz problem >doesn't exist in the latest drivers anymore, if you are interested in that?
Do you meen upgrating to another Ubuntu version?
I've already done :   sudo apt-get dist-upgrade

=> A bit more than that. Upgrading the Linux kernel to the very latest stable kernel, to see if the problem has been fixed sometime during the ~10 months of development since your Linux 4.4 kernel and the latest stable Linux kernel 4.9, just released 2 weeks ago.

You would download the following files by clicking on the links:

http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.9/linux-headers-4.9.0-040900_4.9.0-040900.201612111631_all.deb

http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.9/linux-headers-4.9.0-040900-lowlatency_4.9.0-040900.201612111631_amd64.deb

http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.9/linux-image-4.9.0-040900-lowlatency_4.9.0-040900.201612111631_amd64.deb

Then in a terminal go into the Downloads folder, probably

cd ~/Downloads

Then install the files:

sudo dpkg -i linux-headers* linux-image*
And after that finished, reboot. That would boot into this new Linux 4.9 kernel by default, and then you can see if a 1920x1080 240 Hz refresh works better. This also installs a low-latency kernel for potentially better realtime behaviour. The boot loader menu at system power up/restart allows selection between all installed kernels.

If that wouldn't work, we could go to an even newer kernel, which at this point is just a prototype for the in-development Linux 4.10 kernel. If that wouldn't fix it, i could contact my people at AMD to see if they have an idea, although that would take time given imminent christmas/new year vacation time.


>-> Another thing you could try is keeping the 240 Hz refresh rate, but reduce the display resolution to >1280x1024 if that is sufficient for your purpose, as according to one of your previous posts, that video >resolution also supports 240 Hz and maybe the driver handles that better?
Yes, indeed, there is no trembling any more with these settings. Possibly, I can use this screen size.

=> If you run PerceptualVBLSyncTest with these settings, you should get again very homogeneous black-white flicker - or actually just some solid grey, given that at 240 Hz switching rate there shouldn't be any perceptible black-white transitions anymore. That would be a cue that the monitor can handle 240 Hz also properly at other resolutions than its native 1920x1080 resolution without introducing timing or visual artifacts.

-mario


Thanks! 
Elena

On 22 December 2016 at 07:57, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:
 

XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


Hi Mario,
 just to update,...
after CTRL + F1 and rebooting I have now a normal ubuntu display. So, no worries.

-> Ok, good. However, i wonder how stable that is, and if it can't come back under certain conditions? The trembling you describe and that "blue screen" are likely related. It could be that on average load on the memory you get trembling, but if there is some spike in memory bandwidth demand, the display controller doesn't get enough date for even the leftmost 3/4 of the display and malfunctions harder and that causes that "blue screen". It's quite unclear to me how these things look. Could you create some photos or a short video of it somewhere?

My suspicion why you got that after a reboot would be that the desktop GUI remembered that you prefer the display running at 240 Hz, ie. it stored that setting in a configuration file. Then during login, the desktop GUI switched the display from the default mode of 60 Hz back to 240 Hz.

If this happens again, and you can't easily recover from it, one way to recover is to press CTRL+ALT+F1 for a text console (sorry, i gave you the wrong key combo, it is not CTRL+F1 but CTRL+ALT+F1), login at the text console, and then type:

rm ~/.config/monitors.xml

to delete the file with the display default video settings. Then go back to the GUI with CTRL+ALT+F7 and login normally. That should start the desktop GUI at a safe default video mode for your display of 60 Hz instead of 240 Hz, after the GUI has forgotten your preferred setting.


However,
echo performance > /sys/class/drm/card0/device/ power_dpm_state
echo high > /sys/class/drm/card0/device/ power_dpm_force_performance_ level
commands have not had any positive effect on the 240 Hz display. I still have the same trembling/smearing on 1/4th part if the screen.

-> What confuses me here in your post is that single blank space between /sys/class/drm/card0/device/ and the power_dpm_state and power_dpm_force_performance_ level? Is this a copy & paste / formatting error or did you really have a blank space there? In that case the commands would have failed and done nothing except maybe print some error message?

If you apply above commands, what is the output of:

cat /sys/class/drm/card0/device/ power_dpm_state

and

cat /sys/class/drm/card0/device/ power_dpm_force_performance_ level

Also the full output of the command dmesg would be interesting to see if the driver reports back any errors during switching of video refresh rate to 60 Hz and back to 240 Hz:

echo 4 > /sys/module/drm/parameters/ debug
xrandr -r 60
xrandr -r 240
dmesg > dmesg_log.txt

Creates a text file dmesg_log.txt with that output in the current directory.


At the same time, PTB does not complain and when I run PerceptualVBLSyncTest, the yellow lines are concentrated on the top of the screen.

-> Apart from that smeared right 1/4 of your screen, the output of PTB you posted and the figures look perfect. Everything else seems to work optimally and at least our VBLSyncTest apparently works without dropping any frames at 240 Hz. So if that would work for your experiment script as well, you should be good. If not, there are various ways to tweak the script.

-> Another thing you could try is upgrading to the latest version of the Linux kernel, in the hope that the 240 Hz problem doesn't exist in the latest drivers anymore, if you are interested in that?

-> Another thing you could try is keeping the 240 Hz refresh rate, but reduce the display resolution to 1280x1024 if that is sufficient for your purpose, as according to one of your previous posts, that video resolution also supports 240 Hz and maybe the driver handles that better?

From within PTB scripts you can use SetResolution() to change resolution and refresh rate as long as only one display is connected, e.g.,

oldres = SetResolution (0, 1280, 1024, 240);

to set 1280x1024 at 240 Hz, and

SetResolution(0, oldres);

to restore the previous video settings.

-mario



Elena


*****************************
PerceptualVBLSyncTest

Press ENTER key to start the test. The test will stop after 10 seconds
or any keypress...


PTB-INFO: This is Psychtoolbox-3 for GNU/Linux X11, under Matlab 64-Bit (Version 3.0.12 - Build date: May 13 2016).
PTB-INFO: Support status on this operating system release: Linux 4.4.0-53-generic Supported.
PTB-INFO: Type 'PsychtoolboxVersion' for more detailed version information.
PTB-INFO: Most parts of the Psychtoolbox distribution are licensed to you under terms of the MIT License, with
PTB-INFO: some restrictions. See file 'License.txt' in the Psychtoolbox root folder for the exact licensing conditions.

PTB-INFO: Advanced Micro Devices, Inc. [AMD/ATI] - Tonga PRO [Radeon R9 285/380] GPU found. Trying to establish low-level access...
PTB-INFO: Connected to Advanced Micro Devices, Inc. [AMD/ATI] Tonga PRO [Radeon R9 285/380] GPU with DCE-10.0 display engine [6 heads]. Beamposition timestamping enabled.


PTB-INFO: OpenGL-Renderer is X.Org :: Gallium 0.4 on AMD TONGA (DRM 3.1.0, LLVM 3.8.0) :: 3.0 Mesa 11.2.0
PTB-INFO: VBL startline = 1080 , VBL Endline = 1213
PTB-INFO: Measured monitor refresh interval from beamposition = 4.308817 ms [232.082245 Hz].
PTB-INFO: Will try to use OS-Builtin OpenML sync control support for accurate Flip timestamping.
PTB-INFO: Measured monitor refresh interval from VBLsync = 4.308782 ms [232.084168 Hz]. (50 valid samples taken, stddev=0.003222 ms.)
PTB-INFO: Reported monitor refresh interval from operating system = 4.170855 ms [239.759003 Hz].
PTB-INFO: Small deviations between reported values are normal and no reason to worry.
>>



On 21 December 2016 at 03:05, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:
 

XX-In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


>1. sudo su
>2. Enter admin password.
>3. echo performance > /sys/class/drm/card0/device/ power_dpm_state

>If step 3 doesn't help, try this:

>4. echo high > /sys/class/drm/card0/device/ power_dpm_force_performance_ level

>Any change?

I have done steps 1-3, relaunched the terminal window/matlab, but have not noticed any changes in the display.
Then I have done the step 4 and rebooted the computer.

-> So no improvement, and also not any error message in response to your commands?

After the reboot I had a strange pattern on the screen for 3 seconds and then an empty blue screen forever.
It seems that I spoiled something...

-> You can't have spoiled something, at least not with those commands. Those settings are not persistent over a reboot. They apply immediately and get reset to defaults when the machine restarts. When exactly did the screen turn blue? Did it make it to the login window and only turned blue then? Or already before? If you press CTRL + F1, do you get a proper text console? Does it happen on each reboot? What happens if you connect a different monitor?

-mario



Elena



On 20 December 2016 at 10:19, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:
 

XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


Indeed, after removing the drivers i have now "X.Org :: Gallium 0.4 on AMD Tonga...'
message. PTB  does not generate the errors any more. However, I now have another problem, that I have not had with the amdgpu-pro driver: the right side of the screen (about 1/4 of the screen) is a kind of smeared and trembles. It seems that  the generic driver  does not fully support 240Hz. On the other hand,  I only use the central part of the screen for presentation and the trembling is not seen on the gray background. Is it still unsafe to use 240 Hz refresh mode in this situation?

-> Ok, so the timing and timestamping should be solid if PTB doesn't print any warnings or errors anymore, but that trembling/smear (photo/video would be interesting to judge how those artifacts look) is not nice at all of course. Probably the display controller doesn't get enough memory bandwidth for the fast 240 Hz and the line buffer fifos underflow.

-> Can you post the full output and possibly figures of a run of VBLSyncTest?

We can try to force the driver into choosing a higher performance level, using faster memory clocks, maybe that helps. Try this from a terminal and see if it helps:

1. sudo su
2. Enter admin password.
3. echo performance > /sys/class/drm/card0/device/ power_dpm_state

If step 3 doesn't help, try this:

4. echo high > /sys/class/drm/card0/device/ power_dpm_force_performance_ level

Any change?

You should run VBLSyncTest, and PerceptualVBLSyncTest to see if they show expected results and if the systm is capable of presenting at 240 fps without dropping frames. Timing-wise it should be safe to use the system at 240 Hz even with the artifacts, if you are certain they don't extend into the display area where you actually show your stimuli. But lets see if we can fix this.

-mario

Elena

On 17 December 2016 at 07:27, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:
 

Not sure what happened on your side, but the driver is not properly uninstalled or not uninstalled at all, otherwise it wouldn't say "OpenGL-Renderer is ATI Technologies Inc. :: AMD Radeon R9 200 Series ::" but something like "X.Org :: Gallium 0.4 on AMD Tonga" in that place. That's also the reason for those error messages. Other than that you managed at least to switch the display to 240 Hz mode, so that's a good step forward.

Can your try again, checking the instructions for uninstallation carefully?
-mario





20
Hi Mario,

>=>
If you run PerceptualVBLSyncTest with these settings, you should get again very homogeneous black-white flicker - >or actually just some solid grey, given that at 240 Hz switching rate there shouldn't be any perceptible black-white >transitions anymore. That would be a cue that the monitor can handle 240 Hz also properly at other resolutions than its >native 1920x1080 resolution without introducing timing or visual artifacts.
If I run PerceptualVBLSyncTest with these settings (1280x1024 x240) I get the error (below). And it does not help to run
PsychLinuxConfiguration(), as suggested. So, changing the resolution seem not to be an option.

I will try to update the Linux kernel.

Thank you!
Elena

*********************************************
PTB-INFO: This is Psychtoolbox-3 for GNU/Linux X11, under Matlab 64-Bit (Version 3.0.12 - Build date: May 13 2016).
PTB-INFO: Support status on this operating system release: Linux 4.4.0-53-generic Supported.
PTB-INFO: Type 'PsychtoolboxVersion' for more detailed version information.
PTB-INFO: Most parts of the Psychtoolbox distribution are licensed to you under terms of the MIT License, with
PTB-INFO: some restrictions. See file 'License.txt' in the Psychtoolbox root folder for the exact licensing conditions.

PTB-INFO: Advanced Micro Devices, Inc. [AMD/ATI] - Tonga PRO [Radeon R9 285/380] GPU found. Trying to establish low-level access...
PTB-INFO: Connected to Advanced Micro Devices, Inc. [AMD/ATI] Tonga PRO [Radeon R9 285/380] GPU with DCE-10.0 display engine [6 heads]. Beamposition timestamping enabled.
PTB-WARNING: Your graphics driver doesn't allow me to control syncing wrt. vertical retrace!
PTB-WARNING: Please update your display graphics driver as soon as possible to fix this.
PTB-WARNING: Until then, you can manually enable syncing to VBL somehow in a manner that is
PTB-WARNING: dependent on the type of gfx-card and driver. Google is your friend...

PTB-WARNING: Seems that a Mesa OpenGL software renderer is active! This will likely cause miserable
PTB-WARNING: performance, lack of functionality and severe timing and synchronization problems.
PTB-WARNING: Most likely you are running Psychtoolbox on a Matlab version 8.4 (R2014b) or later and
PTB-WARNING: Matlab is causing this problem by overriding your operating systems OpenGL library with
PTB-WARNING: its own outdated software library. Please run the setup script PsychLinuxConfiguration()
PTB-WARNING: now from your Matlab command window and then quit and restart Matlab to fix this problem.

PTB-WARNING: Actually, it is pointless to continue with the software renderer, as that will cause more trouble than good.
PTB-WARNING: I will abort now. Read the troubleshooting tips above to fix the problem. You can override this if you add the following
PTB-WARNING: command: Screen('Preference', 'ConserveVRAM', 64); to get a functional, but close to useless window up and running.
****************************************************

>>

On 22 December 2016 at 17:12, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

XXX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


Hi Mario,

...

The trembling occurs irrespective of blue or normal screen. When i do 'xrands -r 240 ' thr trembling is there. I attached a photo. (Note that you can't read the text on the left side - my right).


=> Ok, thanks. That photo looks different from what i would have expected. Maybe because it's a photo and not a movie, so one doesn't see the trembling. Or maybe because my suspicion about the cause of the trembling is wrong, and something else goes wrong with signal transmission. Seems to be more the rightmost 1/5th of the display? Why ist the photo left-right flipped?

I removed the empty spaces, and I have not had any error while running the commands.

cat /sys/class/drm/card0/device/ power_dpm_state
 performance

>and
>cat /sys/class/drm/card0/device/ power_dpm_force_performance_ level
auto

=> Looks correct.

the full output of the command dmesg would be interesting to see if the driver reports back any errors during >switching of video refresh rate to 60 Hz and back to 240 Hz:
sudo su
>echo 4 > /sys/module/drm/parameters/ debug
>xrandr -r 60
>xrandr -r 240
>dmesg > dmesg_log.txt
>Creates a text file dmesg_log.txt with that output in the current directory.
I performed these operations and attached the dmesg_log.txt file

=> Thanks. Doesn't show anything suspicious, but captures useful debug info.

Another thing you could try is upgrading to the latest version of the Linux kernel, in the hope that the 240 Hz problem >doesn't exist in the latest drivers anymore, if you are interested in that?
Do you meen upgrating to another Ubuntu version?
I've already done : sudo apt-get dist-upgrade

=> A bit more than that. Upgrading the Linux kernel to the very latest stable kernel, to see if the problem has been fixed sometime during the ~10 months of development since your Linux 4.4 kernel and the latest stable Linux kernel 4.9, just released 2 weeks ago.

You would download the following files by clicking on the links:

http://kernel.ubuntu.com/~ kernel-ppa/mainline/v4.9/ linux-headers-4.9.0-040900_4. 9.0-040900.201612111631_all. deb

http://kernel.ubuntu.com/~ kernel-ppa/mainline/v4.9/ linux-headers-4.9.0-040900- lowlatency_4.9.0-040900. 201612111631_amd64.deb

http://kernel.ubuntu.com/~ kernel-ppa/mainline/v4.9/ linux-image-4.9.0-040900- lowlatency_4.9.0-040900. 201612111631_amd64.deb

Then in a terminal go into the Downloads folder, probably

cd ~/Downloads

Then install the files:

sudo dpkg -i linux-headers* linux-image*
And after that finished, reboot. That would boot into this new Linux 4.9 kernel by default, and then you can see if a 1920x1080 240 Hz refresh works better. This also installs a low-latency kernel for potentially better realtime behaviour. The boot loader menu at system power up/restart allows selection between all installed kernels.

If that wouldn't work, we could go to an even newer kernel, which at this point is just a prototype for the in-development Linux 4.10 kernel. If that wouldn't fix it, i could contact my people at AMD to see if they have an idea, although that would take time given imminent christmas/new year vacation time.


>-> Another thing you could try is keeping the 240 Hz refresh rate, but reduce the display resolution to >1280x1024 if that is sufficient for your purpose, as according to one of your previous posts, that video >resolution also supports 240 Hz and maybe the driver handles that better?
Yes, indeed, there is no trembling any more with these settings. Possibly, I can use this screen size.

=> If you run PerceptualVBLSyncTest with these settings, you should get again very homogeneous black-white flicker - or actually just some solid grey, given that at 240 Hz switching rate there shouldn't be any perceptible black-white transitions anymore. That would be a cue that the monitor can handle 240 Hz also properly at other resolutions than its native 1920x1080 resolution without introducing timing or visual artifacts.

-mario


Thanks!
Elena

On 22 December 2016 at 07:57, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


Hi Mario,
just to update,...
after CTRL + F1 and rebooting I have now a normal ubuntu display. So, no worries.

-> Ok, good. However, i wonder how stable that is, and if it can't come back under certain conditions? The trembling you describe and that "blue screen" are likely related. It could be that on average load on the memory you get trembling, but if there is some spike in memory bandwidth demand, the display controller doesn't get enough date for even the leftmost 3/4 of the display and malfunctions harder and that causes that "blue screen". It's quite unclear to me how these things look. Could you create some photos or a short video of it somewhere?

My suspicion why you got that after a reboot would be that the desktop GUI remembered that you prefer the display running at 240 Hz, ie. it stored that setting in a configuration file. Then during login, the desktop GUI switched the display from the default mode of 60 Hz back to 240 Hz.

If this happens again, and you can't easily recover from it, one way to recover is to press CTRL+ALT+F1 for a text console (sorry, i gave you the wrong key combo, it is not CTRL+F1 but CTRL+ALT+F1), login at the text console, and then type:

rm ~/.config/monitors.xml

to delete the file with the display default video settings. Then go back to the GUI with CTRL+ALT+F7 and login normally. That should start the desktop GUI at a safe default video mode for your display of 60 Hz instead of 240 Hz, after the GUI has forgotten your preferred setting.


However,
echo performance > /sys/class/drm/card0/device/ power_dpm_state
echo high > /sys/class/drm/card0/device/ power_dpm_force_performance_ level
commands have not had any positive effect on the 240 Hz display. I still have the same trembling/smearing on 1/4th part if the screen.

-> What confuses me here in your post is that single blank space between /sys/class/drm/card0/device/ and the power_dpm_state and power_dpm_force_performance_ level? Is this a copy & paste / formatting error or did you really have a blank space there? In that case the commands would have failed and done nothing except maybe print some error message?

If you apply above commands, what is the output of:

cat /sys/class/drm/card0/device/ power_dpm_state

and

cat /sys/class/drm/card0/device/ power_dpm_force_performance_ level


Also the full output of the command dmesg would be interesting to see if the driver reports back any errors during switching of video refresh rate to 60 Hz and back to 240 Hz:

echo 4 > /sys/module/drm/parameters/ debug
xrandr -r 60
xrandr -r 240
dmesg > dmesg_log.txt

Creates a text file dmesg_log.txt with that output in the current directory.


At the same time, PTB does not complain and when I run P
erceptualVBLSyncTest, the yellow lines are concentrated on the top of the screen.

-> Apart from that smeared right 1/4 of your screen, the output of PTB you posted and the figures look perfect. Everything else seems to work optimally and at least our VBLSyncTest apparently works without dropping any frames at 240 Hz. So if that would work for your experiment script as well, you should be good. If not, there are various ways to tweak the script.

-> Another thing you could try is upgrading to the latest version of the Linux kernel, in the hope that the 240 Hz problem doesn't exist in the latest drivers anymore, if you are interested in that?

-> Another thing you could try is keeping the 240 Hz refresh rate, but reduce the display resolution to 1280x1024 if that is sufficient for your purpose, as according to one of your previous posts, that video resolution also supports 240 Hz and maybe the driver handles that better?

From within PTB scripts you can use SetResolution() to change resolution and refresh rate as long as only one display is connected, e.g.,

oldres = SetResolution (0, 1280, 1024, 240);

to set 1280x1024 at 240 Hz, and

SetResolution(0, oldres);

to restore the previous video settings.

-mario



Elena


*****************************
PerceptualVBLSyncTest

Press ENTER key to start the test. The test will stop after 10 seconds
or any keypress...


PTB-INFO: This is Psychtoolbox-3 for GNU/Linux X11, under Matlab 64-Bit (Version 3.0.12 - Build date: May 13 2016).
PTB-INFO: Support status on this operating system release: Linux 4.4.0-53-generic Supported.
PTB-INFO: Type 'PsychtoolboxVersion' for more detailed version information.
PTB-INFO: Most parts of the Psychtoolbox distribution are licensed to you under terms of the MIT License, with
PTB-INFO: some restrictions. See file 'License.txt' in the Psychtoolbox root folder for the exact licensing conditions.

PTB-INFO: Advanced Micro Devices, Inc. [AMD/ATI] - Tonga PRO [Radeon R9 285/380] GPU found. Trying to establish low-level access...
PTB-INFO: Connected to Advanced Micro Devices, Inc. [AMD/ATI] Tonga PRO [Radeon R9 285/380] GPU with DCE-10.0 display engine [6 heads]. Beamposition timestamping enabled.


PTB-INFO: OpenGL-Renderer is X.Org :: Gallium 0.4 on AMD TONGA (DRM 3.1.0, LLVM 3.8.0) :: 3.0 Mesa 11.2.0
PTB-INFO: VBL startline = 1080 , VBL Endline = 1213
PTB-INFO: Measured monitor refresh interval from beamposition = 4.308817 ms [232.082245 Hz].
PTB-INFO: Will try to use OS-Builtin OpenML sync control support for accurate Flip timestamping.
PTB-INFO: Measured monitor refresh interval from VBLsync = 4.308782 ms [232.084168 Hz]. (50 valid samples taken, stddev=0.003222 ms.)
PTB-INFO: Reported monitor refresh interval from operating system = 4.170855 ms [239.759003 Hz].
PTB-INFO: Small deviations between reported values are normal and no reason to worry.
>>



On 21 December 2016 at 03:05, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

XX-In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


>1. sudo su
>2. Enter admin password.
>3. echo performance > /sys/class/drm/card0/device/ power_dpm_state

>If step 3 doesn't help, try this:

>4. echo high > /sys/class/drm/card0/device/ power_dpm_force_performance_ level

>Any change?

I have done steps 1-3, relaunched the terminal window/matlab, but have not noticed any changes in the display.
Then I have done the step 4 and rebooted the computer.

-> So no improvement, and also not any error message in response to your commands?

After the reboot I had a strange pattern on the screen for 3 seconds and then an empty blue screen forever.
It seems that I spoiled something...

-> You can't have spoiled something, at least not with those commands. Those settings are not persistent over a reboot. They apply immediately and get reset to defaults when the machine restarts. When exactly did the screen turn blue? Did it make it to the login window and only turned blue then? Or already before? If you press CTRL + F1, do you get a proper text console? Does it happen on each reboot? What happens if you connect a different monitor?

-mario



Elena



On 20 December 2016 at 10:19, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

XX---In PSYCHTOOLBOX@yahoogroups.com, <orekhova.elena.v@...> wrote :


Indeed, after removing the drivers i have now "X.Org :: Gallium 0.4 on AMD Tonga...'
message. PTB does not generate the errors any more. However, I now have another problem, that I have not had with the amdgpu-pro driver: the right side of the screen (about 1/4 of the screen) is a kind of smeared and trembles. It seems that the generic driver does not fully support 240Hz. On the other hand, I only use the central part of the screen for presentation and the trembling is not seen on the gray background. Is it still unsafe to use 240 Hz refresh mode in this situation?

-> Ok, so the timing and timestamping should be solid if PTB doesn't print any warnings or errors anymore, but that trembling/smear (photo/video would be interesting to judge how those artifacts look) is not nice at all of course. Probably the display controller doesn't get enough memory bandwidth for the fast 240 Hz and the line buffer fifos underflow.

-> Can you post the full output and possibly figures of a run of VBLSyncTest?

We can try to force the driver into choosing a higher performance level, using faster memory clocks, maybe that helps. Try this from a terminal and see if it helps:

1. sudo su
2. Enter admin password.
3. echo performance > /sys/class/drm/card0/device/ power_dpm_state

If step 3 doesn't help, try this:

4. echo high > /sys/class/drm/card0/device/ power_dpm_force_performance_ level

Any change?

You should run VBLSyncTest, and PerceptualVBLSyncTest to see if they show expected results and if the systm is capable of presenting at 240 fps without dropping frames. Timing-wise it should be safe to use the system at 240 Hz even with the artifacts, if you are certain they don't extend into the display area where you actually show your stimuli. But lets see if we can fix this.

-mario

Elena

On 17 December 2016 at 07:27, mario.kleiner@... [PSYCHTOOLBOX] <PSYCHTOOLBOX@yahoogroups.com> wrote:

Not sure what happened on your side, but the driver is not properly uninstalled or not uninstalled at all, otherwise it wouldn't say "OpenGL-Renderer is ATI Technologies Inc. :: AMD Radeon R9 200 Series ::" but something like "X.Org :: Gallium 0.4 on AMD Tonga" in that place. That's also the reason for those error messages. Other than that you managed at least to switch the display to 240 Hz mode, so that's a good step forward.

Can your try again, checking the instructions for uninstallation carefully?
-mario