Created attachment 183208 [details] Video of the build in framerate indicator of my monitor SUMMARY My monitor supports 175Hz with FreeSync Premium. When VRR is enabled and the system doesn't display dynamic content, the framerate reduces automatically, which is fine. In my case, it runs at 48 fps until I interact with the system. Ever since I updated my system from Plasma 6.3 to 6.4.2, the framerate stays at 48, even when the cursor is moved, making it feel very laggy. STEPS TO REPRODUCE 1. enable VRR 2. move cursor OBSERVED RESULT Cursor visibly laggy and not taking advantage of high refresh rate screen. EXPECTED RESULT Framerate increases to match the displays max VRR framerate. SOFTWARE/OS VERSIONS Linux Kernel: 6.15.4 KDE Plasma Version: 6.4.2 KDE Frameworks Version: 6.15.0 Qt Version: 6.9.1 ADDITIONAL INFORMATION
Disabling VRR fixes the issue. The patchnotes of Plasma 6.4.1 mentioned changes to VRR in KWin "Core/renderloop: fix subsurfaces vrr scheduling." I don't know if that commit is to blame, it's just the only mention of VRR I found. I am on Wayland, using Mesa 25.1.4. lspci -nn | grep VGA: 0c:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Navi 21 [Radeon RX 6950 XT] [1002:73a5] (rev c0)
The OpenSuse Slowroll maintainer @bmwiedemann was kind enough to create a kwin6 package with the mentioned commit (https://invent.kde.org/plasma/kwin/-/commit/5a071e0678df7913392572b0f7bb381026e40b02) reverted for testing but it did not change the VRR behavior on my system. I did the same test: setting VRR policy to always and moving the cursor with the displays frame counter enabled.
This sounds exactly like https://gitlab.freedesktop.org/drm/amd/-/issues/3034. Does it still happen on Linux 6.17+?
(In reply to Zamundaaa from comment #3) > This sounds exactly like > https://gitlab.freedesktop.org/drm/amd/-/issues/3034. Does it still happen > on Linux 6.17+? Sorry for the late reply. The issue is resolved on my system. I currently run Kernel-Version: 6.17.7-1