@optonox, I think you will not get a satisfactory answer to your questions.
The issues that manifest this behaviour, as I understand it, are sprawling. The implementation of highDPI on the platform is quite naive, and fragmented due to the various packages handling the rendering, and the various UI libraries used to create the apps. That's before we get to driver vendors etc. I'm just a user, and image processing/computer graphics is my full time job - I wouldn't know where to start contributing. It is going to be a long, long road to a decent experience for High DPI screens and multiple DPI setups. That's my very unhelpful 2 pennies worth, hope it helps. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-control-center in Ubuntu. https://bugs.launchpad.net/bugs/1870736 Title: [nvidia] Screen scaling 125% gives 200% Status in gnome-control-center package in Ubuntu: Confirmed Status in mutter package in Ubuntu: Confirmed Bug description: Procedure used: 1. Fully updated system via apt update && apt upgrade 2. Select the screen setup in gnome control center 3. Click the "Fractional scaling" toggle 4. Select 125% and click the green "use" button top right (it says "Anvend" in dansih) 5. Observe that the window has grown a lot, click the "use new settings" button 6. The window tells me, I am at 200% scaling. The "200%" option is now highlighted. 7. Switch back to 100% and file this bug. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: ubuntu-release-upgrader-core 1:20.04.16 ProcVersionSignature: Ubuntu 5.4.0-21.25-generic 5.4.27 Uname: Linux 5.4.0-21-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia ApportVersion: 2.20.11-0ubuntu22 Architecture: amd64 CrashDB: ubuntu CurrentDesktop: ubuntu:GNOME Date: Sat Apr 4 09:42:34 2020 InstallationDate: Installed on 2018-01-14 (810 days ago) InstallationMedia: Ubuntu 16.04.3 LTS "Xenial Xerus" - Release amd64 (20170801) PackageArchitecture: all ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=da_DK.UTF-8 SHELL=/bin/bash SourcePackage: ubuntu-release-upgrader Symptom: release-upgrade UpgradeStatus: Upgraded to focal on 2020-04-03 (0 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-control-center/+bug/1870736/+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
