I have a very odd problem I am trying to wrap my head around… ever since updating from kernel 5.16.9 to anything higher, the Gnome desktop has been quite sluggish. After trying out a few things I found that when running glxgears the framerate stays often below 60hz, or the refresh rate of my two monitors. Looking like this for example:
glxgears
Running synchronized to the vertical refresh. The framerate should be
approximately the same as the monitor refresh rate.
217 frames in 5.0 seconds = 43.397 FPS
177 frames in 5.0 seconds = 35.301 FPS
169 frames in 5.0 seconds = 33.683 FPS
184 frames in 5.7 seconds = 32.391 FPS
163 frames in 5.0 seconds = 32.518 FPS
265 frames in 5.0 seconds = 52.838 FPS
274 frames in 5.0 seconds = 54.693 FPS
275 frames in 5.0 seconds = 54.826 FPS
When doing nothing, just having a Chrome window open, it drops to a steady 55 fps. Moving the window around or switching desktops or anything else makes it drop even more.
However: when running glxgears without sync to refresh rate, there is no problem.
vblank_mode=0 glxgears
ATTENTION: default value of option vblank_mode overridden by environment.
117004 frames in 5.0 seconds = 23400.729 FPS
109880 frames in 5.0 seconds = 21975.996 FPS
111736 frames in 5.0 seconds = 22347.018 FPS
119470 frames in 5.0 seconds = 23893.951 FPS
120343 frames in 5.0 seconds = 24068.547 FPS
120781 frames in 5.0 seconds = 24156.186 FPS
121270 frames in 5.0 seconds = 24253.859 FPS
Interestingly, when running glxgears without vertical sync, the desktop becomes snappy as it should be.
Running the same test without overriding vblank_mode on the older kernel 5.16.9 gives the following result, which is basically as expected:
glxgears
Running synchronized to the vertical refresh. The framerate should be
approximately the same as the monitor refresh rate.
306 frames in 5.0 seconds = 60.998 FPS
300 frames in 5.0 seconds = 59.997 FPS
299 frames in 5.0 seconds = 59.792 FPS
300 frames in 5.0 seconds = 60.000 FPS
300 frames in 5.0 seconds = 59.997 FPS
298 frames in 5.0 seconds = 59.598 FPS
My setup is this:
AMD Ryzen 3900X
AMD 5500XT GPU (Navi 14)
kernel 6.1.2
Gnome 43.2 on Wayland
two 4k displays @ 60hz
Any ideas how to fix this? It is really a bit annoying…