Brand new Manjaro and Arch Linux user checking in.
So I had the inevitable ‘wtf’ moment on my rather substantial Intel i5 Desktop, Dragging a window across the screen seemed to cause KDE to reach 9% CPU in Htop, that I can live with, but it seemed to be really, really laggy, like 2 FPS. It occurred to me to check out what effects were causing the problem, so I opened up compositor. I saw that OpenGL2.0 was selected as the renderer, so I tried 3.0 and the lag was just as bad,
Looks like your on-chip graphics is not working for some reason, try to run something like glxinfo -B and post output here.
The output to glxinfo -B is:
name of display: :0
display: :0 screen: 0
direct rendering: Yes
Extended renderer info (GLX_MESA_query_renderer):
Vendor: Intel Open Source Technology Center (0x8086)
Device: Mesa DRI Intel(R) HD Graphics 4600 (HSW GT2) (0x412)
Version: 21.2.1
Accelerated: yes
Video memory: 1536MB
Unified memory: yes
Preferred profile: core (0x1)
Max core profile version: 4.5
Max compat profile version: 3.0
Max GLES1 profile version: 1.1
Max GLES[23] profile version: 3.1
OpenGL vendor string: Intel Open Source Technology Center
OpenGL renderer string: Mesa DRI Intel(R) HD Graphics 4600 (HSW GT2)
OpenGL core profile version string: 4.5 (Core Profile) Mesa 21.2.1
OpenGL core profile shading language version string: 4.50
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile
OpenGL version string: 3.0 Mesa 21.2.1
OpenGL shading language version string: 1.30
OpenGL context flags: (none)
OpenGL ES profile version string: OpenGL ES 3.1 Mesa 21.2.1
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.10
but then I tried XRender and PRESTO! I am getting totally fluid graphical response times, even though it uses about 12% CPU versus the 9% that OpenGL uses in conjunction with the on-chip graphics of my i5.
So it’s fixed for now, hopefully this can help someone else who has a similar setup to mine.
In the future, when providing code/output, please copy-paste that output in-between 3 backticks ``` at the beginning and end of the code/text so that the output looks like this:
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
instead of like this:
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.`
(as that makes both our lives much easier)
No need to do anything right now as I’m a moderator here on this site and have fixed it for you already. However, in the future I might not see your post so review my RAW edits by pushing the orange pencil in the upper right corner of the post I just fixed. 
XRender is a legacy compositing backend that uses CPU to draw the desktop so it’s not fixed, it’s just worked around. GPU still doesn’t work but I can’t say what’s wrong as it needs some more research.
There is a bug in the most recent release of xorg. Downgrading xorg-server and xorg-server-commons to 1.20.13-1 will fix it.
See also:
I changed back to OpenGL 3 and it works properly. no idea why. Could be related to a few power cycles.
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