2560x1440@144Hz not running at full 144Hz with "force composition pipeline" enabled

No real difference. Around 5% on kwin and 2% on Xorg, force pipeline on or off. Everything else is insignificant.

Real mystery, slowdowns reported but no cause. I guess you’ll have to wait for other users reporting the same.

That’s a shame but I guess there’s not much else I can do for now. Anyway, thank you for your time at least.

Update

On the latest driver (460.32.03), “force composition pipeline” now works correctly if the second monitor is disabled, or more interestingly, if I lower the resolution to 1920x1080@144Hz on the main monitor. Previously the latter only worked if the monitor was connected over DVI but now it seems to work just fine over DP.

Is there anything I could do to help find out why 2560x1440@144Hz with a second monitor connected still feels sluggish when “force composition pipeline” is enabled? I tried lowering the resolution and refresh rate of the second monitor, as well as only enabling “force composition pipeline” on the main monitor but no luck.

Update again

On the latest driver (460.67), everything works as expected even with second monitor on, but only up to 120Hz. Almost there, the drivers seem to be slowly improving!

I just wanted to state here that I have had a very similar problem.
I am currently using driver version 495.44 on Linux with a GTX 3080 with two 4k 60hz displays via displayport 1.2 and 1.4 (LG 27UK850 and LG 27UL850).
I get terrible screen tearing that is apparent even while scrolling on web pages.
When I activate force composition pipeline, the screen tearing is fixed, but the apparent framerate drops to 30Hz (confirmed with framerate comparison videos on youtube). Reported framerate in games is at 60Hz.
When I reduce the display resolution to 2560x1440 or switch to HDMI, force composition pipeline works as intended and there is no apparent loss of framerate.

I had kind of forgotten about this but I’ll give another update. According to my earlier posts, everything was working fine if I disabled the second monitor. However, now no matter what, if “force composition pipline” is enabled on the 2560x1440 monitor, it looks very choppy at 144 Hz. If I set both to 120 Hz it’s good but it would be a shame to throw away those extra frames.

This is on driver 470.86 because 495 has that dbus log spamming issue, though I don’t think it was any different on that version when I briefly tried it.