Alright, I tested again on a more powerful intel chip. Its an 7th generation i7 chip. Same generation but i7 instead of i3 and this time I got different results. Also I would like to note that this time both desktop environments were tested on Fedora 40 in a live environment. Instead of testing one on endeavour and the other on Fedora. Plasma was on version 6.0.3 on Fedora 40’s live environment.
Gnome:
Moving Windows:
cpu: 20% --- same as before
gpu: 7% render --- gnome used slightly less gpu here compared to the i3 chip.
Firefox Playback:
cpu: 45% --- same as before
gpu: alternated between 15% and 50% approximately every 5 seconds for render, 25% video decode. --- slightly higher than on the i3 chip plus I identified the frequency of the spikes to happen around every 5 seconds.
Mpv Playback:
cpu: < 11% --- negligible difference than before.
gpu: 60% render, 20% video decode --- this was the biggest change; 20% less on the more powerful chip.
KDE:
Moving Windows:
cpu: 25% --- a good bit higher than on the i3 chip. This is 11% more than before.
gpu: 21% render --- negligible difference to the i3 chip.
Firefox Playback:
cpu: 22 % --- slightly higher than the i3 chip.
gpu: 35% render, 25% video decode -- this is quite a bit higher than before. Slightly more video decode, but twice as much render.
Mpv Playback:
cpu: < 8% -- negligible difference
gpu: 70% render, 20% video decode - a good bit less than before in terms of rendering, and slightly less in video decode.
kwin used a bit shy of 10% render here.
New conclusions. Kwin seemed to add an additional 10% of gpu usage to pretty much all tasks. Plasma is still more gpu heavy compared to Gnome as I concluded in the last test. Plasma used bit more cpu in desktop operations compared to Gnome unlike with the i3 chip where it used a bit less cpu. I considered 10% more to be a non-negligible difference.
Firefox consistently uses more cpu under Gnome compared to Plasma for some reason. This could be some bug in either Gnome or Firefox because I don’t understand why that happens. Firefox’s gpu utilization appeared to be a more consistent under Plasma than Gnome. I’m not sure if that is a good thing or not though. For all I know maybe its supposed to clock up and down the way that it appeared to do so on Gnome.
On the mpv side of things is where we saw the biggest change. Gnome used a considerable bit less gpu this time around. About 20% less than on the i3 chip. I saw the same dip for plasma, but it still uses about 10% more render than Gnome. Both appeared to use less decode. They both dropped about 5% in video decode usage.
As a quick summary, mpv performed better under Gnome and this seems to be directly caused by kwin. If you noticed above that mpv’s gpu usage was 10% higher on plasma. That extra 10% came from kwin. Gnome shell never showed up under intel_gpu_top. That is how negligible its impact was on the applications. I still don’t understand the higher firefox cpu usage under Gnome though. Mpv performed the same cpu wise.
Anyways, we can never rule out hardware issues, since I only have a finite amount of hardware. Some of the numbers are so close that they are within margin of error for recording. One thing that I can conlude is that kwin consistently uses more CPU and GPU than Gnome’s mutter. However, that did not seem to effect applications all that much.