Syncing issue with windows 10


I am a new Matlab, and therefore Psychtoolbox, user that have a couple of problems trying to run various syncing test. I tried to follow the instructions in the “help SyncTrouble” section (changed my vsync setting, for example), but nothing worked. I also updated my drivers. I have to admit that me being a complete beginner may be the cause here.

I run Windows 10
CPU : AMD Ryzen 7 4700U with Radeon Graphics
8 Cores
GPU/APU : AMD Radeon Graphic (no more details could be found)

PsychtoolboxVersion give me this output:
ans =

'3.0.17 - Flavor: beta - Corresponds to SVN Revision 12153
 For more info visit:'

VBLSyncTest gives me this output :


ans =


PTB-INFO: This is Psychtoolbox-3 for Microsoft Windows, under Matlab 64-Bit (Version 3.0.17 - Build date: Apr 13 2021).
PTB-INFO: OS support status: Windows 10 (Version 10.0) supported and tested to some limited degree.
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: For information about paid priority support, community membership and commercial services, please type
PTB-INFO: ‘PsychPaidSupportAndServices’.

PTB-INFO: OpenGL-Renderer is ATI Technologies Inc. :: AMD Radeon™ Graphics :: 4.6.14739 Compatibility Profile Context 21.6.1 27.20.22001.14011
PTB-INFO: VBL startline = 1080 , VBL Endline = 1107
PTB-INFO: Measured monitor refresh interval from beamposition = 16.660943 ms [60.020613 Hz].
PTB-INFO: Will use beamposition query for accurate Flip time stamping.
PTB-INFO: Measured monitor refresh interval from VBLsync = 16.657064 ms [60.034590 Hz]. (50 valid samples taken, stddev=0.345161 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-INFO: ==============================================================================================================================
PTB-INFO: WINDOWS DWM DESKTOP COMPOSITOR IS ACTIVE. On this Windows-10 or later system, Psychtoolbox can no longer reliably detect if
PTB-INFO: this will cause trouble for timing and integrity of visual stimuli or not. You might be just fine, or you could be in trouble.
PTB-INFO: Use external measurement equipment and independent procedures to verify reliability of timing if you care about proper timing.
PTB-INFO: ==============================================================================================================================

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


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.

Error using PsychImaging (line 2330)
Error using Screen
See error message printed above.

Error in VBLSyncTest (line 295)
w = PsychImaging(‘OpenWindow’,screenNumber, 0, [], [], [], stereo);

using Screen(‘Preference’, ‘SkipSyncTests’, 1); does allow me to bypass those issue and see the test screens. I also tested the %make movie function in the “help Screen” section, which only work with the given line.

I know that this bug doesn’t prevent me to develop an experimental design, it just make using my laptop as a testing device inadvisable, but I’m not sure that I won’t have to use it to do exactly that, so would like to have the flexibility if possible.

I tried to follow to posting guide, but sorry if I missed any important information.

Thank you.

Read through that carefully and follow any suggestions. If you still can’t resolve it, then the most viable solution is to dual-boot your laptop with Ubuntu where such driver/OS errors with low-level access to the GPU are rare.

What Ian says. Also for additional diagnostics:


Thanks, I’ll see if I can find anything else in the documentations.

All of my prof/supervisors are using Linux anyway, so I’ll may be peer pressured into it at some point.

Thanks again for your time.

Sound like a good type of peer pressure, if it nudges you to use the right tools for the job.