SUMMARY Global scaling does not work for panel, icons on desktop, etc. These are extremely small on a HiDPI monitor. Also, sometimes text on Konsole will look weird and overlapping with each other. I can't reproduce it now because that happens randomly. Global scaling worked before with the environment variable PLASMA_USE_QT_SCALING=1. It broke after a recent update. I checked and can confirm that this environment variable is still set but is no longer effective. I am using X11 session (I can't try Wayland because I have a lot of windows there and it will take me a lot of time to re-open everything because Wayland does not have session restore). STEPS TO REPRODUCE 1. Set global scale to 150% 2. Logout and login OBSERVED RESULT Panel, icons on desktop, etc, are not scaled. EXPECTED RESULT Everything are scaled. SOFTWARE/OS VERSIONS KDE Plasma Version: 5.27.9 KDE Frameworks Version: 5.112.0 Qt Version: 5.15.11
I find that the scaling works properly with my laptop monitor. It just fails to work with my external monitor.
This is an X11-specific issue. It's fixed (well, kind of) in Plasma 6. You can work around it yourself for now by adding PLASMA_USE_QT_SCALING=1 in /etc/environment. *** This bug has been marked as a duplicate of bug 356446 ***
(In reply to Nate Graham from comment #2) > This is an X11-specific issue. It's fixed (well, kind of) in Plasma 6. You > can work around it yourself for now by adding PLASMA_USE_QT_SCALING=1 in > /etc/environment. > > *** This bug has been marked as a duplicate of bug 356446 *** As I have mentioned in the bug report, this environment variable is already set. It worked perfectly before but it not now. Also, it actually still works on my laptop monitor but not on my external monitor.
Yes, it breaks mixed-DPI multi-monitor setups. This is unfortunately a known limitation of hidpi on X11. F If that environment variable worked before and then broke, I have a recollection of that being a bug that got fixed for Plasma 5.27.10. If I'm mis-remembering, and it's still broken, then unfortunately there's nothing to be done here since that environment variable is not officially supported and we make no guarantees that it will work. or a better hidpi experience, I recommend the Wayland session.
I am not sure if I need to open a new issue, but I find that the problem is not only related to scaling. If I connect the monitor to my laptop through a particular USB-C hub, the followings will happen: 1. If on X11, there is scaling problem as mentioned above. 2. If on Wayland, the external monitor simply does not work. In System Settings, the monitor is detected, but when I try to enable it, nothing will happen. If I reopen the System Settings, the enable checkbox will be unchecked. This is the case even if I don't use scaling at all. If I connect the monitor to another USB-C port of my laptop without going through the hub, or if I use another USB-C hub, everything will work fine. However, I am quite sure that the particular USB-C hub is working fine because before I login, the external monitor works properly in SDDM. It also works on TTY.
In general, please open new bug reports for new issues. That said, multi-monitor setups are known to work very poorly on X11, so I recommend using Wayland if you want a chance at a decent multi-monitor experience. Bugs reported for multi-monitor issues on X11 are likely to be ignored, TBH.