SUMMARY On wayland "Present Windows" animation is laggy. Its not that bad but noticeable compared to how smooth it is on xorg. I tried setting all Latency options in Compositor settings but still no change. other animations like wobbly windows seems to work fine. On x11 session, running GPU heavy task in background and bunch of windows open, its still smooth compared to Wayland. This problem did not occur when I tested 5.21.0. But I'm now on 5.21.5 and did not checked wayland in between so cant say which version this bug affects from. STEPS TO REPRODUCE 1. Log into Wayland session. 2. Open more than 10 windows 3. toggle "Present Windows" OBSERVED RESULT laggy Animation EXPECTED RESULT smooth animation as x11 SOFTWARE/OS VERSIONS Linux/KDE Plasma: (available in About System) KDE Plasma Version: 5.21.5 KDE Frameworks Version: 5.81.5 Qt Version: 5.15.2+kde+r192-1 ADDITIONAL INFORMATION CPU: Intel i7-8565U (8) @ 4.600GHz iGPU: Intel UHD Graphics 620 dGPU: Radeon 520 Mobile (muxless, uses iGPU to render) tested on both GPUs by setting DRI_PRIME before `startplasma-wayland` command and getting same result
Cannot reproduce FWIW.
On Wayland, we don't do triple buffering. This does make a difference with less powerful GPUs such as integrated Intel GPUs.
(In reply to smit from comment #0) > This problem did not occur when I tested 5.21.0. But I'm now on 5.21.5 and > did not checked wayland in between so cant say which version this bug > affects from. Sorry. This is not correct. I was using linu-zen(https://liquorix.net). I switched to vanilla linux-lts recently and that's when I noticed this issue. I'm again now on linux-zen and I can't notice stuttering/laggyness. Its still there if I closely look for it but its not that noticeable and it's completely gone (becomes smooth as x11) if I set Latency to the "Prefer smoother animations". So I can't say this started from 5.21.0.
If changing kernels fixes the issue, then it clearly is an issue with the graphics driver you end up using. There might be things we could do from KWin on it but it's rather limited as we are as good as the graphics drivers are anyway. If you find any ideas why this could be report it and if we get to reproduce it maybe we have a chance at addressing it.