Created attachment 113845 [details] kwin support info + xrandr output I have 144hz monitor, refresh rate is set at 143.86hz (idk why not 144) but desktop remains locked at 60fps. Tried nearly every setting combination: vsync, compositor backend, animation, scale method, disabling effects. Tried removing second monitor. Disabling compositing increases fps to 144hz. Monitor 1: Asus MG279Q (1440p, 144hz). Freesync disabled. Monitor 2: LG E2350 (1080p, 60hz) GPU: RX580 + amdgpu Not sure what other info i should provide.
According to the output you have two screens: one is 144 Hz and one with 60 Hz. X11 doesn't support per screen refresh rates, so the minimum of the attached screenshot is used.
Disconnecting monitor results in fps increase indeed, but it remains stuck at about 70fps. Oddly enough disabling vsync locks it at 60fps while enabling some form of vsync allows it going up to 75fps.
Since there was no reply for a day im reopening this because i still get max 75fps on 144hz monitor while having only one monitor connected. Any ideas about that?
From where do you get the information that it is 75 fps?
"Show FPS" desktop effect.
I just tested KDE neon unstable ISO. X11 session still runs at decreased FPS, no matter if 60hz monitor on or off. Wayland session runs at decreased FPS if 60hz monitor is on. Turning it off makes main 144hz montior run at full speed with compositor enabled. Yay! As X11 development is done we probably can not expect a fix. That is fine. Wayland still needs to be able to run monitors at different refresh speeds.
(In reply to Rokas Kupstys from comment #5) > "Show FPS" desktop effect. Just as an FYI: Show FPS effect is not a benchmark (the reported refresh rate does not say anything about the refresh rate KWin is capable of). Furthermore show fps is capped and cannot show 144 Hz.
How should i benchmark it? I really only used said effect to get some numbers. What i really do is grab a window and rapidly drag it in the circular motion. Archaic method but it is clearly visible when desktop is rendered at 144hz and when at ~60hz. I do same thing on windows as well. On windows and plasma wayland with one monitor this motion is silky smooth while on X11 or wayland+second 60hz monitor it is clearly visible that window skips more space between frames.
There's no way to benchmark this and your benchmark method does not show anything except the window movement speed of X11 which unsurprisingly does not reach 144 Hz.
Anyway lets close this. AFAIK X-related development has stopped for plasma/kwin and there probably is little point in spending time to fix this. Wayland already has this working for single monitor and per-monitor refresh rate support is planned so issue is on your radar already. Thanks!