Q100642: Low framerates in Mari 4.8 and 5.0 due to VSync



Users may notice that the FPS displayed in the Canvas is lower in Mari 5.0 and 4.8, compared to previous releases.

For example, on a 60Hz monitor, the Canvas FPS in Mari will appear ‘limited’ to 60 or fewer frames-per-second.

If you are experiencing low framerates, even while working on very simple projects, then you may need to turn off VSync.


VSync (Or vertical sync) aims to prevent screen-tearing by synchronising the number of frames being generated with the monitor’s refresh rate.

In Mari 4.7 and earlier, enabling or disabling VSync was controlled by a preference (under Preferences > GPU > General > VSync), as shown in the Mari documentation page on the Preferences dialog:

Mari Documentation: Mari Preferences Dialog 

Mari’s Qt library was upgraded in versions 4.8 and 5.0. The newer version of Qt does not permit changing VSync settings while Mari is running. Therefore, the VSync preference has been replaced by an environment variable that must be set prior to launching Mari:


While you may have disabled VSync in Mari 4.7 and earlier via the preferences, you will need to use this environment variable to turn it off starting with Mari 4.8 and 5.0.

When this variable has not been set, VSync is controlled by the system and driver settings (e.g. for NVidia graphics cards, the setting in the NVidia Control Panel will be used)


To resolve the issue, please try turning VSync off by setting the MARI_VSYNC environment variable to a value of 0:


On Windows, you can create a new Environment Variable by going to Control Panel > System > Advanced System Settings > Environment Variables:


On Linux, the method to set environment variables depends on the default shell. For example, for a bash shell, you will need to edit the .bashrc file in your home directory and add the following line:

export MARI_VSYNC=0

You may need to restart your computer for these environment variables to take effect.

NOTE: For further information on setting environment variables, please refer to the following article: Q100015: How To Set Environment Variables

After setting the environment variable and launching Mari, the canvas framerate should no longer be limited.

Please note that if the FPS in the Canvas is faster than the monitor’s refresh rate, this could result in screen tearing.

Below is a table of MARI_VSYNC’s expected values and their effects:




VSync off


VSync on

No value/not set

VSync controlled by the GPU driver settings


If you are still experiencing difficulties, please create a support ticket to let us know the exact issue encountered and the troubleshooting steps that have been taken.

For more information on how to open a support request, please refer to this article: Q100064: How to raise a support ticket

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