System-wide slowdown since Plasma 6.1

[joobert]

My system has been beyond sluggish ever since Plasma 6.1 released on Fedora, and I just found forceblur to be the culprit. This was especially bad when watching videos, even moving the mouse would cause the video to stutter and drop to around 10fps, so forget about multitasking. I'm on a 12th gen Intel NUC for reference.

This sluggishness was completely eliminated when I disabled forceblur, re-enabled native blur, and restarted my system.

[taj-ny]

I haven't noticed any performance issues on my laptop with an Intel GPU, even during 4k60fps playback. How many blurred windows do you have open when the issue occurs?

This sluggishness was completely eliminated when I disabled forceblur, re-enabled native blur, and restarted my system.

So the sluggishness persists even after disabling force blur until you restart the system?

Edit: Wayland or X11?

[joobert]

I'm on Wayland. Even with just one window open the sluggishness was obvious, but got worse with opening more windows.

I restarted my system just because, noticed the improvement before doing so. The difference is night and day.

[taj-ny]

I did find something that could be causing performance issues, but I doubt that's it. Try the performance-test branch. Disable anti-aliasing if you're using rounded corners, otherwise KWin will crash.

If that doesn't fix it then I don't know what the cause is. I've seen some people complain about bad performance on 6.1 (https://www.reddit.com/r/kde/comments/1dkhfvl/is_it_only_me_or_has_anyone_elses_desktop, https://discuss.kde.org/t/plasma-6-1-did-something-changed-in-performance-for-intel-cpus/17519), so it could be just a KWin bug.

[joobert]

Just tested the performance-test branch and disabled anti-aliasing on rounded corners, still the same sluggishness as before. This has to be related to some sort of conflict with triple buffering IMO.

I really only use this plugin to fix the actual blur ignoring/going out of the rounded corner radius bounds on blurred windows, so hopefully that gets integrated into KWin native blur in the future.

[taj-ny]

#85 could also be related, I fixed it on develop.

Does the corner radius affect performance?