Bug 495367

Summary:	Adaptive Sync (VRR) not working after update 6.2.2
Product:	[Plasma] kwin	Reporter:	cannubis <cannubis>
Component:	platform-drm	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	calvinatorzcraft, cannubis, nate
Priority:	NOR	Keywords:	regression
Version First Reported In:	6.2.2
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description cannubis 2024-10-26 01:58:10 UTC

SUMMARY
I would like to report a bug with FreeSync (VRR) in KDE Plasma 6.2.2. I experience screen tearing while gaming, despite having the Plasma adaptive sync setting set to automatic or enabled. Using Gamescope with the --adaptive-sync parameter resolves the issue, indicating a Plasma-specific problem. I have tested this on three similar AMD setups, including one fresh install, and the issue persists

STEPS TO REPRODUCE
1. Open Display Settings
2. Set adaptive sync to automatic or always on
3. Play a game like Baldur's Gate 3, or any other isometric title

OBSERVED RESULT
Screen tearing occurs while moving the camera with the mouse or arrow keys, both vertically and horizontally.

EXPECTED RESULT
No screen tearing should occur while moving the camera with the mouse or arrow keys.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Archlinux/KDE Plasma
KDE Plasma Version: 6.2.2
KDE Frameworks Version: not installed
Qt Version: 5.15.15

ADDITIONAL INFORMATION
I have restarted several times and tested three different PCs. FreeSync appears to work better in third-person games like Cyberpunk 2077 and The Witcher 3, where tearing is less noticeable. However, in isometric games like Baldur's Gate 3 and Divinity: Original Sin 2, screen tearing is prominent during camera movements.
Tearing is less noticeable at lower frame rates (60-80 FPS) and more apparent at 140-165 FPS. I use Mango to lock the frame rate to 165 Hz (my monitor's refresh rate) and have tried lowering the cap to 160 and 150, but that didn’t help.

Comment 1 cannubis 2024-10-26 02:05:03 UTC

PC specs:
CPU: AMD Ryzen 7 7800X3D 8-Core Processor
GPU: AMD Radeon RX 7900 XTX
RAM: 32GB 6000 Corsair Vengance
MOBO: Asus Rog StrixB650E-i
SSD: M.2 Samsung 980PRO
Monitor: LG UltraGear 27" Freesync 165Hz

Comment 2 cannubis 2024-11-02 16:44:12 UTC

UPDATE:

I’ve since observed a more critical issue affecting game performance.
For example, Kingdom Come: Deliverance now struggles to maintain stable frame rates, dropping from 90 FPS down to as low as 30 FPS. Strangely, when launching the game through Gamescope, performance consistently exceeds 100 FPS, sometimes reaching over 200 FPS. Previously, performance through Gamescope closely matched or slightly underperformed compared to standard Plasma, which has been my default setup for gaming. I have also noticed around a 10 FPS drop in Cyberpunk 2077, along with intermittent stuttering.

Comment 3 calvin 2024-12-14 06:37:41 UTC

This got much worse after a recent update, if I run mpv on a 240hz with a disable adaptive sync window rule it still flickers around the 230-250hz range while it previously would have been locked at 240hz

Comment 4 calvin 2024-12-14 06:38:42 UTC

(In reply to calvin from comment #3)
> This got much worse after a recent update, if I run mpv on a 240hz with a
> disable adaptive sync window rule it still flickers around the 230-250hz
> range while it previously would have been locked at 240hz

oh shoot wrong bug thread