thegreyshadow: Great info here, thanks!
I upgraded and so far I managed to test just two games (I'm absorbed into Linux due to work crunch, and when I have some spare time I'm playing Planescape: Torment EE also in Linux).
Worked flawlessly, no problem:
Torchlight.
Had problems with
The Talos Principle.
Initially I installed the Talos Principle in Win10 and experienced stuttering. These got fixed once I capped framerate at 30 fps.
After upgrading into Windows 11 the stuttering came back, even with framerate capped to 30 fps.
(btw, if anyone knows a workaround I'd be grateful).
Will update as I play more games, but I expect it won't be that soon.
There are three things i would suggest you should try. Lower your mouse polling rate, in case the value is set to 1000hz or above. Depending your model you can set it to 900, 800 or 500hz.
I wouldn't necessarily try anything below 500hz as this can also cause unwanted behavior... Disable all overlays in: Galaxy (in case you use it), ANSEL, GameDVR, XBOX gaming overlay.
Activate V-Sync.
If it's a graphics card driver issue, maybe downloading and using the revision you used in Windows 10 can help solve this issue.
Edit: If you got an NVIDA GPU, switch to Display and click Adjust Desktop Size and Position. Set perform scaling to Display if it is set to GPU or vice versa. It might help to also activate Override the scaling mode set by games and programs to see whether this elminiates the stuttering.