This bug doesn't belong here. I found out, that this is most probably a problem with the switching mechanism between intel and nvidia drivers, which doesn't seem to do its job fully under certain conditions. What was causing gnome-shell to do what it was doing was actually some strange bug that was preventing the fans from working properly sometime after the first CPU throttle, which affected the graphics card performance and/or CPU performance and led to overall problems.
I ended up reinstalling the system twice and playing with all sorts of things, but I don't know how certain things exactly work, so I won't put this somewhere else for now (although in the end it should probably be filed under nvidia-drivers). For those who may run into a similar situation: The best bet is to install the nvidia-drivers right after the system using the built-in driver installation tool (software-properties-gtk). Don't touch anything else, don't change the drivers later! Don't use the nvidia-xconfig tool, unless you know exactly what you are doing. If you want to switch between intel and nvidia drivers, use nvidia-settings and always restart the system (don't just logout/login). If you can't switch back to nvidia drivers, use prime-switch nvidia and reboot. ** Changed in: gnome-shell (Ubuntu) Status: Incomplete => Invalid -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-shell in Ubuntu. https://bugs.launchpad.net/bugs/1807096 Title: [nvidia] gnome-shell uses 100% cpu, triggered by games while using nvidia-driver To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1807096/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs