There is an OpenGL vsync bug in macOS Ventura 13.0 and 13.1 that affects vsync detection in PsychoPy. If you run “timeByFrame.py” or “timeByFramesEx.py” (see Demo->timing), you will see dropped frames and a mean win.frameIntervals that is incorrect (shows an odd bimodal distribution). For example, o…

I’m also having this problem in MacOS Ventura 13.2.1 [image] "TimeByFrames" script and quantisation error Coding Any more developments on this topic? I’m getting the same thing on multiple Macs running MacOS 13.2., using both the native and external displays. Some of the…

Unfortunately, the problem still persists in Ventura 13.3. Possible solution in Ventura is to use UTM and install Monterey or Ventura under UTM and run PsychoPy in UTM. Remarkably, using Ventura under UTM more or less fixes the problem as UTM seems to set the refresh to 60 Hz independent of the actu…

OpenGL vsync bug in macOS Ventura affects frame flip detection in PsychoPy

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danielkimmel March 31, 2023, 5:53pm 2

I’m also having this problem in MacOS Ventura 13.2.1

Anyone have any fixes/workarounds for this?

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OpenGL vsync bug in macOS Ventura affects frame flip detection in PsychoPy

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