Bug 493450 - Framerate briefly drops from 60 FPS to ~30 FPS on KDE Plasma / Wayland
Summary: Framerate briefly drops from 60 FPS to ~30 FPS on KDE Plasma / Wayland
Status: REPORTED
Alias: None
Product: kwin
Classification: Plasma
Component: performance (show other bugs)
Version: 6.1.4
Platform: Arch Linux Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2024-09-21 16:50 UTC by nullity98
Modified: 2024-09-23 18:38 UTC (History)
1 user (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:

Attachments
KWin performance data - logging in without Show FPS effect (95.15 KB, text/csv)
2024-09-21 16:50 UTC, nullity98 		Details
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Description nullity98 2024-09-21 16:50:20 UTC 
Created attachment 173941 [details]
KWin performance data - logging in without Show FPS effect

I’ve been getting framerate drops on KDE Plasma from 60 FPS to ~30 FPS. The problem usually goes away after entering the desktop overview or changing applications. I enabled the “Show FPS” Desktop Effect in settings to monitor the drops, and with that on the screen the problem completely goes away. However it does mean I have something always on my screen which I don't want.

Information about my setup:

- Arch Linux
- KDE Plasma 6 (6.1.4)
- Wayland
- Nvidia GeForce RTX 4070 (nvidia-open 560.35.03)
- HiDPI DisplayPort monitor
- ICC profile enabled for color correction

Steps to reproduce:

- Log in
- Perform an action such as holding down the up arrow to go through command history in Konsole

KWin framerate drops noticeably with subsequent actions like scrolling, dragging around the window, or showing the Dock at the bottom. As far as I can tell, other things like video playback and gaming remain unaffected.

KWin performance data for without the Show FPS effect is attached). I also have one for with the Show FPS effect but it looks like I can only attach a single file. If there's a way I can attach that one as well do let me know.

Also worth noting is that I tried setting `KWIN_DRM_DISABLE_BUFFER_READABILITY_CHECKS=1` which changed the behavior of the problem from low framerates to flickering of updated areas on the screen. Just like before, the problem went away with the "Show FPS" Desktop Effect enabled.