HiDPI support in KDE Plasma has been recently improved! I’m afraid what’s not improved is the procedure for using that. In this post I’ll detail the steps to use HiDPI with KDE if you have a high resolution display (for example, I have that in my Linux Dell M3800).
Remember that the settings you change will not be applied completely until you logout and login again into KDE.
First of all, you need to go in Settings, then
“Display and Monitor” -> “Display Configuration“. If you scroll down you see a “Scale Display” button
Click on that and in the “Screen Scaling” dialog, drag the “Scale” in the middle, corresponding to a scale factor of 2 and press OK.
Then go back to the main page of Settings, select “Font“, and force to the DPI font to 168. (or even more if you want).
Apply the settings, logout and login again into KDE and you’ll enjoy your HiDPI display with a scale factor of 2, which basically means it will be usable 🙂
Be warned, KDE applications will look correctly, but there’ll still be other applications which might not have been implemented with HiDPI in mind… and they’ll still look horrible even with the scaling you set.
I’d changed Scale and logged in/out several times, and couldn’t figure out why nothing had changed. Having to change the fonts DPI manually AS WELL is certainly counter-intuitive, so thanks for the info!
For me it was the other way round:
I was happy finding the DPI adjustment in the font settings but I found that increasing this had mixed results, i..e the effect was not even for different UI elements, so I also had to adjust font sizes and many icons remained quite too small.
I assume, everyone who has found one of these settings will not consider that their may be a second one, so thanks for sharing this indispensable advice.
It would be helpful if some sane settings would be applied automatically in initial login.
I also found a video on this, which also shows how to adjust the height of a plasma panel (which is not affected by display scaling): https://youtu.be/5Kz2E5Xy5tw
Isn’t easier to inform Xorg as to the correct monitor size, as explained in the Xorg ArchWiki?
But then everything will look unreadable… or did you mean something else?
The problem is, the thing in the real world that drives the need for scaling, I.e. the size of a given monitor and its dpi, is a per-monitor phenomena. Monitor scaling really needs to be settable differently for each monitor. An extremely common case is someone hooking up their laptop to an external monitor. the chance of these having radically different dpis is is high.
And @ericjs, what can I do? I have this issue. One laptop with two external monitors. I’ve not been able to set it properly.