Same problem: Lenovo Z50, Radeon R6 R7 graphics, AMD FX 7500 CPU. The bug is definitely corresponds to the new Ubuntu version because the previously 16.04 version worked almost smoothly. (I changed it because of very slow boot process - it is a bit faster in 18.04).
Nect to the overheating the system often freezes. The desktop stops, freezes and after half a minit everything is will be almost fine. I could check it and the same time CPU usage was extremely high. The problem presents both Wayland and Xorg but uder Xorg it is less frequently. -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-nouveau in Ubuntu. https://bugs.launchpad.net/bugs/1768976 Title: Ubuntu 18.04 is overheating after upgrade from 16.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1768976/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp