Testing tearing - and trying to fix it - on my graphics card I noticed, that nvidia-driver for linux ignores __GL_SYNC_TO_VBLANK=0 for the desktop enviroment / shell. It registers __GL_SHOW_GRAPHICS_OSD=1 and show indicators on every part of the shell, but the vblank is there indicated as active. I am currently trying to test my suspicion, that vsync on plasmashell causes stutters on videoplayback if you open another window (think videoprojection and preparing assets during the screening; or gl render with OBS and stutters in the video). Now, I am tryning this on KDE, but Gnome has also vsync always on, even if there is the enviroment variable declared very low level (/etc/enviroment or desktop enviroment startup script).

I did test my laptop with RTX2060 and desktop with GTX1660. Both KDE and Gnome.

Anyone?? any tip

Can you post the result of glxgears running with __GL_SYNC_TO_VBLANK=0 and __GL_SYNC_TO_VBLANK=1? This way you can actually verify if vsync is off or not. You can’t judge this just by looking for tearing, because even if an application runs with vsync OFF, the window manager (WM) will still vsync the final output unless you disable vsync in the WM or disable its compositing (in KWin for example, you can toggle compositing on/off with Alt+Shift+F12.)