SUMMARY on a 4K screen when you have scaling to 150% and set "scaled by the system"(it is quite improved in plasma 6.3 even though some blur remains) it glitches all fullscreen/borderless windowed applications/games. STEPS TO REPRODUCE 1. Have 4K screen set to 150% fractional scaling and set "scaled by the system" for legacy x11 applications 2. Start a game for example which uses xwayland - most games on steam through proton OBSERVED RESULT The game gets locked to 1440p max resolution it doesn't let you pick 4K EXPECTED RESULT To be able to pick 4K resolution(3840x2160) without issues SOFTWARE/OS VERSIONS Operating System: CachyOS Linux KDE Plasma Version: 6.3.0 KDE Frameworks Version: 6.10.0 Qt Version: 6.8.2 Kernel Version: 6.13.2-1-cachyos-bmq (64-bit) Graphics Platform: Wayland Processors: 16 × AMD Ryzen 7 5800X3D 8-Core Processor Memory: 31,3 GiB of RAM Graphics Processor: NVIDIA GeForce RTX 3090
I'm having this same exact issue. Games launched via Steam Proton are being rendered in 1440p at 150% for me which is actually breaking interlaced 3D that requires native resolution. I have not tested native games.
>1. Have 4K screen set to 150% fractional scaling and set "scaled by the system" for legacy x11 applications setting this means it is expected that the application will not see the native resolution, as the system is scaling it.
Choose the other scaling setting if you want games to have native resolution
(In reply to David Edmundson from comment #3) > Choose the other scaling setting if you want games to have native resolution That was the first thing I tried and it still doesn't work.
Had to log out and back in for the change to take effect. Maybe it should be noted somewhere when changing the setting?
I have also observed that his affects native wayland(you can use proton cachyos to try the native wayland and the game is locked to 1440p regardless of the global scaling chosen)
My mistake: after talking with a KWin developer, it's actually not expected that it fails to take effect immediately. That's what should be fixed, so I'm changing the title to reflect it.
Git commit 6913ab9e4f34a99cc1e07077a9d85feacc05dc10 by Xaver Hugl. Committed on 04/03/2025 at 15:54. Pushed by zamundaaa into branch 'master'. workspace: watch kdeglobals and update Xwayland scale accordingly The code assumed that KScreen would send KWin a new output configuration, and thus Workspace::applyOutputConfiguration would run when the Xwayland scale setting is changed. If you only change that setting and no other output setting though, that doesn't happen, so until this setting is moved into the normal configuration mechanism, we have to update the Xwayland scale when the config value in kdeglobals changes. M +1 -0 src/main.cpp M +6 -0 src/main.h M +22 -11 src/workspace.cpp M +2 -0 src/workspace.h https://invent.kde.org/plasma/kwin/-/commit/6913ab9e4f34a99cc1e07077a9d85feacc05dc10
Git commit 86264ec740cb035fb1213771fe686af2b9099c80 by Xaver Hugl. Committed on 04/03/2025 at 17:03. Pushed by zamundaaa into branch 'Plasma/6.3'. workspace: watch kdeglobals and update Xwayland scale accordingly The code assumed that KScreen would send KWin a new output configuration, and thus Workspace::applyOutputConfiguration would run when the Xwayland scale setting is changed. If you only change that setting and no other output setting though, that doesn't happen, so until this setting is moved into the normal configuration mechanism, we have to update the Xwayland scale when the config value in kdeglobals changes. (cherry picked from commit 6913ab9e4f34a99cc1e07077a9d85feacc05dc10) M +1 -0 src/main.cpp M +6 -0 src/main.h M +22 -11 src/workspace.cpp M +2 -0 src/workspace.h https://invent.kde.org/plasma/kwin/-/commit/86264ec740cb035fb1213771fe686af2b9099c80