Indeed, if you prefer long term stability then you should stay on 20.04. We will be backporting some performance fixes to 20.04 as soon as it is safe to do so. In fact a couple are coming in mutter 3.36.4 and another in 3.36.5...
If you want to make 4K significantly faster on 20.04 in a safe way right now, then I recommend forcing it to use the old Intel driver which is better at frequency scaling. Just edit /etc/environment and add a new line: MESA_LOADER_DRIVER_OVERRIDE=i965 and then reboot. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to mutter in Ubuntu. https://bugs.launchpad.net/bugs/1890802 Title: Big performance degradation in X11 + 4K resolution + fractional scaling in second monitor compared to Wayland Status in mutter package in Ubuntu: Won't Fix Bug description: Laptop: Lenovo ThinkPad L480 Graphics: Intel UHD Graphics 620 (KBL GT2) Second monitor: Philips 276E8VJSB/00 4K UHD There is a big performance degradation in an X11 session + 4K resolution + 125% fractional scaling in the second monitor compared to a Wayland session. The mouse cursor moves very slow, dragging Windows is very slow, scrolling in Firefox is very laggy, so everything becomes unusable. The performance degradation applies in both displays even though fractional scaling is only applied in the second 4K monitor. Whereas in Wayland, the performance is much better in 4K resolution + fractional scaling in the second monitor, the mouse cursor and dragging windows are a lot smoother. I just sometimes notice a slight jump in the mouse cursor but only in the second monitor, the built-in monitor behaves normally. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: mutter 3.36.3-0ubuntu0.20.04.1 ProcVersionSignature: Ubuntu 5.4.0-42.46-generic 5.4.44 Uname: Linux 5.4.0-42-generic x86_64 ApportVersion: 2.20.11-0ubuntu27.6 Architecture: amd64 CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME Date: Fri Aug 7 12:00:26 2020 InstallationDate: Installed on 2020-04-26 (102 days ago) InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423) ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=de_DE.UTF-8 SHELL=/bin/bash SourcePackage: mutter UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/1890802/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
