First, thank you for what seems to be a great distro. I am very new to Manjaro and RPi but a long time Linux user on x86_64.
Using the 20.08 release, Xorg is horribly slow. glxinfo does show hardware acceleration, but it is very laggy, including keyboard and mouse use. There does not appear to be anything running in the background which would cause this. Using glxgears, I see around 20 fps on a 4k monitor, just horrible.
If I boot with Ubuntu 20.04 LTS, I see 200+ fps and all is good. I will dig deeper and find the cause but thought I would post here to see if others experiencing this issue?
In chasing this down… this will “fix” the issue.
$ pacman -S xf86-video-fbdev
Then edit /boot/config.txt and comment out the following:
#dtoverlay=vc4-fkms-v3d
And now reboot
I still need to resolve a monitor resolution issue but the lag is gone and
glxgears now reports above 300 fps. So fbdev is better than VC at the moment.
If you are going that route you did not say if you changed the gpu_mem= value. It needs to be at least 320 and probably be better with 512 for that monitor. You did not say also if you had hdmi_enable_4kp60=1 set in config.txt for thaat monitor.
It was a fresh image with updates applied, stock settings. If those modifications will resolve the issue, I will be happy run with them. Unfortunately I will have to wait until tomorrow to try it as I do not have access to a 4k at home.
Eh, I asked before taking a look in the Manjaro Repo. I would prefer to stay in the official repo when possible. And at this point, since it ain’t broke, don’t fix it.
I tried this but it stopped my pi from booting afterwards until I reverted the changes using my laptop. I installed the package and commented out the line in config.txt successfully, is there anything I may be missing?
Hmm, well… there could be, depending on what you may have modified. But commenting out dtoverlay=vc4-fkms-v3d in config.txt will prevent the VC video drivers from loading. Installing xf86-video-fbdev will supply the fbdev driver and it should load without any further configuration. Check /var/log/Xorg.0.log you should see messages concerning fbdev being loaded. If you see it is being loaded and then subsequently unloaded, it is finding a different video driver to load.
You are running Xorg and not Wayland, correct? This only works for Xorg.
I do not know what you have going on in your config.txt but you have xf86-video-fbturbo-git installed evidently for it to show “OpenGL renderer string: llvmpipe” instead of “OpenGL renderer string: V3D 4.2” So you have no gpu aceleration.
I do not think that glxgears reports right some times. As far as the Pi OS I have seen mis-reporting with labeling (as in what glxgears sees) in their forums in the past. If they have V3D rendering now I am not aware of it. They had not in the past. The frame rate you reported above is more in line with llvmpipe in what it reports.