Bug 480078 - Artifacts and tearing while dragging windows only under 4k high refresh rate with UI global scale
Summary: Artifacts and tearing while dragging windows only under 4k high refresh rate ...
Status: RESOLVED UPSTREAM
Alias: None
Product: kwin
Classification: Plasma
Component: compositing (show other bugs)
Version: 5.27.10
Platform: Arch Linux Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2024-01-20 02:20 UTC by Eduardo
Modified: 2024-02-15 19:51 UTC (History)
1 user (show)

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


Attachments
Video showing the artifacts (3.75 MB, video/mp4)
2024-01-20 02:20 UTC, Eduardo
Details

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Description Eduardo 2024-01-20 02:20:27 UTC
Created attachment 165059 [details]
Video showing the artifacts

I got a new monitor and I started experiencing visual artifacts while dragging windows, specially if the window being dragged overlaps with the taskbar.

The taskbar displays some flickering, and the window displays some crazy tearing/rectangular holes. Difficult to explain in words, please see attached video for clarification.

For me this only happens on the 4k resolution (3840x2160) AND using refresh rates either 144Hz or 160Hz, AND using 150% scaling factor (might happen on other scaling factor).

If I put 4k 120Hz or below, the bug doesn't trigger, it needs at least 144Hz to trigger. If I lower the resolution to anything below 4k, it doesn't happen. If I use 100% scaling, it doesn't happen, even on 4k 160Hz. So you need these 3 conditions to trigger it: 4k, 144Hz+, and a scaling factor like 150%.

STEPS TO REPRODUCE
1. Own a 4k+high refresh rate monitor
2. Set the resolution to 4k, the refresh rate to at least 144Hz, and the global scaling factor to 150%.
3. Drag some window overlapping the taskbar

OBSERVED RESULT
Crazy tearing/rectangular holes on the window being dragged, and flickering on the taskbar.

EXPECTED RESULT
Smooth dragging with no artifacts

SOFTWARE/OS VERSIONS

Operating System: Arch Linux 
KDE Plasma Version: 5.27.10
KDE Frameworks Version: 5.114.0
Qt Version: 5.15.12
Kernel Version: 6.1.71-1-lts (64-bit)
Graphics Platform: X11
Processors: 12 × Intel® Core™ i7-8700K CPU @ 3.70GHz
Memory: 31,3 GiB of RAM
Graphics Processor: NVIDIA GeForce RTX 4090/PCIe/SSE2

nVidia driver version 535.113.01
Comment 1 Nate Graham 2024-02-15 19:51:36 UTC
This is almost certainly a problem in the proprietary NVIDIA drivers.

Please report this issue to the NVIDIA folks, either by sending an email to linux-bugs@nvidia.com or making a post at https://forums.developer.nvidia.com/c/gpu-graphics/linux. It would be helpful to the NVIDIA developers if you could run nvidia-bug-report.sh and attach the resulting file in your report. Thanks!