Screen flickering on Ubuntu 20.04 with Nvidia 495 under high CPU

us flag

I'm having a strange issue for the past couple of months.

I run an Ubuntu 20.04 on a Lenovo Y740 laptop (RTX 2070). With the latest Nvidia drivers (currently, I'm testing with 495), I'm having an issue with screen flickering when the CPU is on high load. The heavier the load, the heavier the flickering.

I captured this video to demonstrate:

I have to rollback to as early as 418. The problem completely goes away (but I have problems with suspend, which is a different story).

I tried setting modeset=1 ( with no luck.

I can't understand if this is solely a driver issue or if it's hardware related (I'm on warranty).

Anyone else faced something similar before?

ChanganAuto avatar
us flag
Try enabling force full composition.
U.V. avatar
cn flag
i also updated recently and had this issue... thanks for the rollback hint.
U.V. avatar
cn flag
i have also issues with Nvidia495 on an ubuntu 20.04 with a GeForce GTX 1060 6GB. but I think 470 was ok for me. I try to roll back now.
us flag

I found a work around until the bug gets fixed with a driver update. That problem seems to be related to the CPU frequency on Ubuntu 18.04/20.04. I limited the CPU frequency to 2.6GHz using cpupower-gui on all CPUs and it works fine. It is now stable on Ubuntu with driver 470 and 495. Clearly not ideal.

Kos Prov avatar
us flag
Didn't work for me
Cedric avatar
us flag
Have you selected all CPUs?

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