I have exactly same problem, I've tried both 440, and 435 Nvidia drivers. the results of:
$ xrandr --verbose --output HDMI-0 --scale 2x2 screen 0: 6880x2880 1820x762 mm 96.00dpi crtc 0: 3440x1440 59.97 +0+0 "HDMI-0" xrandr: Configure crtc 0 failed crtc 0: disable crtc 1: disable crtc 2: disable crtc 3: disable crtc 4: disable crtc 5: disable crtc 6: disable screen 0: revert crtc 0: revert crtc 1: revert X Error of failed request: BadValue (integer parameter out of range for operation) Major opcode of failed request: 140 (RANDR) Minor opcode of failed request: 21 (RRSetCrtcConfig) Value in failed request: 0x0 Serial number of failed request: 72 Current serial number in output stream: 72 $ xrandr --verbose --output HDMI-0 --scale 1.25x1.25 screen 0: 4300x1800 1137x476 mm 96.00dpi crtc 0: 3440x1440 59.97 +0+0 "HDMI-0" xrandr: Configure crtc 0 failed crtc 0: disable crtc 1: disable crtc 2: disable crtc 3: disable crtc 4: disable crtc 5: disable crtc 6: disable screen 0: revert crtc 0: revert crtc 1: revert X Error of failed request: BadValue (integer parameter out of range for operation) Major opcode of failed request: 140 (RANDR) Minor opcode of failed request: 21 (RRSetCrtcConfig) Value in failed request: 0x0 Serial number of failed request: 72 Current serial number in output stream: 72 -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-shell 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 gnome-shell 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
