Bug 494675

Summary:	Screen tearing and lag when moving windows diagonally
Product:	[Plasma] kwin	Reporter:	Antonio <antonio.tigri>
Component:	compositing	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED DUPLICATE
Severity:	normal	CC:	mapatrapa, xaver.hugl
Priority:	NOR
Version:	6.2.0
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Antonio 2024-10-13 15:38:15 UTC

SUMMARY
After updating to KDE Plasma 6.2, started experiencing tearing and lagginess issues when moving/dragging windows around.

STEPS TO REPRODUCE
1. Drag a window diagonally (any angle should reproduce the problem).

OBSERVED RESULT
Window tears and doesn't move smoothly (with a low framerate).


EXPECTED RESULT
Same or similar smoothnes than when windows are dragged strictly vertically/horizontally


SOFTWARE/OS VERSIONS
Linux: Linux 6.11.3-zen1-1-zen
KDE Plasma Version: 6.2
Qt Version: 6.7.3-2

ADDITIONAL INFORMATION
using wayland
using optimus manager to only use dedicated gpu (nvidia)
nvidia-drm module loaded and parameters active
nvidia module loaded and EnableGpuFirmware=0
Reproduced with a laptop + 2 external monitors setup. Never reproduced in laptop screen. For the external monitors, sometimes happens on both, sometimes happens in only one.

Comment 1 Jesus 2024-10-13 19:50:39 UTC

Confirmed, the same thing happens to me with an nvidia graphics card as well. The problem disappears if I have any window maximized on a virtual desktop, if I move another window over the maximized one everything works smoothly.

Comment 2 Zamundaaa 2024-10-13 21:10:47 UTC


*** This bug has been marked as a duplicate of bug 494547 ***

Comment 3 Antonio 2024-10-15 20:11:38 UTC

(In reply to Zamundaaa from comment #2)
> 
> *** This bug has been marked as a duplicate of bug 494547 ***

Mine is not an issue of artifacts or flickering, and changing that environment variable does not resolve the issue either. The problem is specifically slowness when moving windows diagonally or shaking the mouse when it becomes big (also diagonally).

Current version is  6.2.0-2 so I am not sure if it is actually related to 494547 and the problem is that arch does not have that update yet, but nothing changed from 6.2.0-1