Sync Failure on OSX El Capitan

1

Hi,


I am trying to use Psychtoolbox on Mac OSX El Capitan but cannot pass the sync test (I know that Linux is the best choice, but the OS/hardware is not my decision to make...).


OSX:         10.11.6 (15G1611)

Hardware: Mac Pro (Late 2013)

Graphics:  AMD FirePro D500 3072 MB

PTB Version: 3.0.14

Matlab 2016a, 2017a

(I installed the latest kernel driver and I checked that it was loaded)


I tried everything I found on the official FAQ pages and also tried some hacks I found online (like switching to a lower screen resolution and switching back). I wonder if there is anyone who uses PTB without sync failure on El Capitan and, if so, how...


Thanks in advance!

Taka


----- Here's the info from PTB -----

PTB-INFO: This is Psychtoolbox-3 for Apple OS X, under Matlab 64-Bit (Version 3.0.14 - Build date: Jun  6 2017).
PTB-INFO: Support status on this operating system release: OSX version 10.11 is not officially supported or tested at all for this release.
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: OpenGL-Renderer is ATI Technologies Inc. :: AMD Radeon HD - FirePro D500 OpenGL Engine :: 2.1 ATI-1.42.15
PTB-INFO: Renderer has 3072 MB of VRAM and a maximum 2965 MB of texture memory.
PTB-INFO: VBL startline = 1080 , VBL Endline = 1241
PTB-INFO: Measured monitor refresh interval from beamposition = 8.333622 ms [119.995845 Hz].
PTB-INFO: Will use beamposition query for accurate Flip time stamping.
PTB-INFO: Measured monitor refresh interval from VBLsync = 8.463376 ms [118.156155 Hz]. (424 valid samples taken, stddev=0.610044 ms.)
PTB-INFO: Reported monitor refresh interval from operating system = 8.333333 ms [120.000000 Hz].
PTB-INFO: Small deviations between reported values are normal and no reason to worry.
PTB-INFO: Stereo display via Anaglyph Red-Green stereo enabled.

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


2
Have you tried VBLSyncTest first? I'm on Sierra, but on a MBP I don't get sync 
errors normally. You appear to be running a 120Hz monitor, what happens if you set it to 60Hz? 

Is there a reason not to upgrade to Sierra? I very much doubt it would make a difference, but PTB states it is not tested with anything but the latest version of macOS...
3
tattooed.tentacle

Thanks. I tried to run VBLSyncTest with a 60Hz LCD monitor but still got the same sync error. Thanks for the suggestion though. Have you ever used PTB on El Capitan or just on Sierra?

Taka

----
>> VBLSyncTest
PTB-INFO: Connection to Psychtoolbox kernel support driver instance #0 (Revision 1) established.

ans =

     0



PTB-INFO: This is Psychtoolbox-3 for Apple OS X, under Matlab 64-Bit (Version 3.0.14 - Build date: Jun  6 2017).
PTB-INFO: Support status on this operating system release: OSX version 10.11 is not officially supported or tested at all for this release.
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: OpenGL-Renderer is ATI Technologies Inc. :: AMD Radeon HD - FirePro D500 OpenGL Engine :: 2.1 ATI-1.42.15
PTB-INFO: Renderer has 3072 MB of VRAM and a maximum 2965 MB of texture memory.
PTB-INFO: VBL startline = 1050 , VBL Endline = 1087
PTB-INFO: Measured monitor refresh interval from beamposition = 16.679828 ms [59.952655 Hz].
PTB-INFO: Will use beamposition query for accurate Flip time stamping.
PTB-INFO: Measured monitor refresh interval from VBLsync = 16.676893 ms [59.963207 Hz]. (299 valid samples taken, stddev=0.205337 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.

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.

This will seriously impair proper stimulus presentation and stimulus presentation timing!
Please read 'help SyncTrouble' for information about how to solve or work-around the problem.
You can force Psychtoolbox to continue, despite the severe problems, by adding the command
Screen('Preference', 'SkipSyncTests', 1); at the top of your script, if you really know what you are doing.
4
Hi, I've used PTB and El Capitan before when that was the current version of the OS. As Mario suggests, this is possibly a hardware + software issue with the MacPro, and you probably should investigate if dual-booting Linux would solve the timing problem. I still much prefer macOS for day-to-day computing tasks; but as Mario rightly states, for scientific research there is a strong imperative to use a system that guarantees data fidelity, timing is important for many vision research tasks, PTB has by far the best low-level control available, PTB works best on Linux, and therefore given the above one should be using Linux unless there is a really good reason not to... 

I still develop code on my Macbook Pro and iMac, but I now won't run experiments using macOS (or Windows for that matter). Apple have abandoned OpenGL, and as usual are pushing their own solution, Metal, that is not designed for the specific requirements of vision research. They have a clear track record of pushing something unique to their platform, then slowly letting it die on the vine...
5
Mario

Thanks for your inputs! You are right, the OSXCompositorIdiocyTest failed as well. It was really good to know that I shouldn't spend any more time on trying to get around the problem.


tattooed.tentacle,

Thanks again for sharing your experience. Yeah, although I am not in a position to make that decision, I can see that upgrading to Linux is a way to go. 

Thanks,
Taka