I'm having similar problems in 1:91.10.0+build1-0ubuntu0.20.04.1 with Thunderbird's CPU usage well over 25 % and for long periods and additionally causing root process Xorg to consume 15 % CPU.
See also: https://bugzilla.mozilla.org/show_bug.cgi?id=1772673 The workaround for me is: gfx.webrender.force-disabled = true ** Bug watch added: Mozilla Bugzilla #1772673 https://bugzilla.mozilla.org/show_bug.cgi?id=1772673 -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to thunderbird in Ubuntu. https://bugs.launchpad.net/bugs/1959747 Title: [upstream] Very high CPU and slow responsiveness in Thunderbird 91 Status in Mozilla Thunderbird: Confirmed Status in thunderbird package in Ubuntu: Triaged Bug description: Very high CPU and slow responsiveness in Thunderbird 91.5.0. Just moving the mouse cursor over a message list results in 365% CPU for me. I had to set this in the config editor to fix it: gfx.webrender.force-disabled = TRUE Upstream bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1730423 To manage notifications about this bug go to: https://bugs.launchpad.net/thunderbird/+bug/1959747/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
