Comment 4 for bug 1769857

Daniel van Vugt (vanvugt) wrote :

"VSync" and "PRIME Sync" are unrelated things. You need to ignore the fact that they sound similar. You should be able to achieve perfect VSync regardless of the "modeset" option. But it may be disabled by default (by Nvidia) as alluded to earlier.

The "NV-GLX" error sounds expected... In a Wayland session you're using Xwayland which doesn't yet connect to the Nvidia driver properly. So avoid Wayland sessions in your case - they're not expected to work for this.

So I think you need to:
  1. Don't use nvidia-drm.modeset=1
  2. Only use Xorg sessions.
  3. Now if tearing is your only problem then look in nvidia-settings for options to fix that. You might also find some xorg.conf options that help here: http://us.download.nvidia.com/XFree86/Linux-x86_64/390.25/README/xconfigoptions.html

gdm3 has nothing to do with any of this. It just launches X and the Nvidia driver dictates what features are supported or not. If you want the maximum features and performance from Nvidia then you usually need to be using a Xorg session and not "modeset".