Bug 513749

Summary:	When screencasting using portal cursor movement causes stutters in games over time
Product:	[Plasma] kwin	Reporter:	Oleg <dreamkepeer>
Component:	screencasting	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	nate
Priority:	NOR	Keywords:	efficiency-and-performance
Version First Reported In:	6.5.4
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	Cursor movement causing stutter in Arma 3 during recording with gpu-screen-recorder kscreen console log Shake cursor stop stuttering

Description Oleg 2025-12-23 16:39:34 UTC

SUMMARY
If I record my screen using gpu-screen-recorder with portal backend and play some games eventually cursor movement start to cause stuttering. Stuttering stops when I disable/stop GSR. Not any game is affected, I have this issue primarily in Arma 3.

STEPS TO REPRODUCE
1. Start Arma 3
2. Start recording using gpu-screen-recorder
3. Play for a while 
4. Start moving cursor.

OBSERVED RESULT
Cursor movement will cause heavy stutter. Interestingly, when "shake cursor" effect engages cursor movement doesn't cause stuttering anymore.

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 6.5.4
KDE Frameworks Version: 6.21.0
Qt Version: 6.10.1
Kernel Version: 6.18.2-3-cachyos (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 9800X3D 8-Core Processor
Memory: 64 ГиБ of RAM (62.4 ГиБ usable)
Graphics Processor: AMD Radeon RX 6700 XT
Manufacturer: ASUS

ADDITIONAL INFORMATION
I've got a feeling this issue somehow connected to VRAM saturation since Arma 3 is heavy on a VRAM, but in my video I didn't hit VRAM limit, and it still stutters. I can reliably reproduce this issue under heavy VRAM consumption scenarios. There's no such issue with drm backend of gpu-screen-recorder. I also using "RADV_PERFTEST=nogttspill" environment variable.

Comment 1 Oleg 2025-12-23 16:42:13 UTC

Created attachment 187911 [details]
Cursor movement causing stutter in Arma 3 during recording with gpu-screen-recorder

Comment 2 Oleg 2025-12-24 18:05:15 UTC

Created attachment 187948 [details]
kscreen console log

Just to clarify, I'm playing on 1440p 115% scaled HDR and VRR enabled monitor if that helps. Attached kscreen-console output.

Comment 3 Oleg 2025-12-26 20:42:07 UTC

Created attachment 188004 [details]
Shake cursor stop stuttering

Stuttering stops when Shake cursor effect engages. And when I move cursor to another while game window is active it's still stuttering.