it depends on certain animated elements visible on the screen
some avatars and achievements are the worst offenders for using high amounts of GPU
even with most of the settings in steam tuned all the way down/off.
the best scene i can find is to look at your library, but not at any specific game.
user's avatars in game can have the effect of animations without even noticing it.
so typically, if possible...log off the steam friend list and play your game
the worst i can find is: your activity feed. user avatars are animated here
hovering on achievements (especially the shiny glowing ones)
the more animations are playing, each one takes an additional amount of GPU to process.
ideally, steam should stop animations if it is not the active window.
you can see steam's gpu/cpu usage activity with something like
NVTOP or nvidia-smi
or HTOP, etc.
Nothing extracted yet.
Your system information
steam-logs.tar.gz
Please describe your issue in as much detail as possible:
I do not understand why, or how, but when I have the Steam client at all visible on my second monitor, any app, Steam game or even other non-steam related apps will lag horrifically on my main monitor.
This only happens with the steam client is visible, and not with any other app, even if they are more demanding on resources (eg. Firefox open while playing a video in 1080p) which deters me from thinking that my pc simply isn't powerful enough. Lag goes away when you minimize the app.
Doctors ask you what you think is wrong with you even if they have an idea of what is wrong with you, so I will do something similar. If I had to point anywhere, I would assume that the client doesn't properly communicate with the X11 server as I did not have this issue when I was using KDE Plasma on Wayland not too long ago (I do not recommend. Too much bloat. Wallpaper Engine wasn't worth it.)
Steps for reproducing this issue: