Bug 515340

Summary: Jitter
Product: [Plasma] kwin Reporter: Alberto Salvia Novella <es20490446e>
Component: compositingAssignee: KWin default assignee <kwin-bugs-null>
Status: REPORTED ---    
Severity: normal    
Priority: NOR    
Version First Reported In: 6.5.5   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: system-info.txt

Description Alberto Salvia Novella 2026-01-31 12:06:12 UTC
Created attachment 189095 [details]
system-info.txt

Desktop animations show quite inconsistent performance, in the form of jitter. Sometimes animations are butter-smooth, others they are completely choppy.

I have tried isolating the cause, but I was unable to. The only differences I could tell are these:

- If you install optimus-manager and nvidia-open, and use X11, animations are always smooth. On both the internal and external screen. Still they are inconsistent on Wayland.

- If you run OBS on Wayland, with the display as source, animations will always show jitter.

Things I have tried without perceiving a clear difference:

- Using the modesetting driver, or nvidia-open, or nvidia proprietary.
- In "/etc/profile.d/optimus.sh" doing "export __NV_PRIME_RENDER_OFFLOAD=1" and "export __GLX_VENDOR_LIBRARY_NAME="nvidia". Or the opposite "export __EGL_VENDOR_LIBRARY_FILENAMES="/usr/share/glvnd/egl_vendor.d/50_mesa.json"".
- Using an external monitor, or only the internal one.
- Setting multiple Kwin Environment Variables.
Comment 1 Alberto Salvia Novella 2026-01-31 12:13:15 UTC
Record:
https://youtu.be/S_psPtSO4fQ