Executive summary:
use __NV_PRIME_RENDER_OFFLOAD=1 __GLX_VENDOR_LIBRARY_NAME=nvidia with care with an HDMI screen.
Longer story:
Disclaimer: I have an Asus Rog Strix laptop with an RTX2060 on Debian testing, with drivers from Nvidia’s website, not the Debian ones.
Currently on kernel 6.4.x.
I’ve been “blessed” with constant stuttering from my DE (KDE). I first thought that it was the software and past kernel 6.1.x and nvidia drivers 515.x.x, I was fighting with my system: constant stutter, had to unplug the HDMI cable and replug it to unlock the screen at times.
The 4K HDMi cable is of high quality, please read on.
To confirm my thoughts, I installed Gnome and experienced the exact same issue.
None if I switched to Wayland, with reduced performance. So not an issue with the connecting hardware.
Trust me, even web surfing with Firefox was a bet.
Solution
Back to X11, i decided to remove all the environment variables related to the ones in the summary.
Since then, no more issue, and no reduced performance either.
I can finally enjoy working on my laptop again.
What I report here may or may not help you or even work for you; but it may be worth to investigate if you have the same issue as I did.
Cheers,