Question about screen resolution in plasma 5 using x11 and a 4 K monitor arrangement.

[René J.V. Bertin]

On Sunday March 13 2022 09:55:31 Stakanov wrote:

>Obviously the problem is not the graphics card, nor the monitor and the 
>monitor is branched with DP on DP. 
>The other monitor is a smaller Medion MD20666 which runs with 60 Hz on its 
>native resolution (1920x1080). 

Have you tried using each monitor separately?

It's my experience that XOrg doesn't always detect OR present the full range of resolutions. A typical one being missing from the list is the quite common 1366x768 resolution of (democratically priced ^^) small screens.

The solution is to define the resolution you want via xrandr and then add it to the monitor where it's missing:

For instance, to ensure I can run a distro on an external drive in VIrtualBox without messing up my desktop layout:
> xrandr --verbose --newmode "1366x768" 85.25 1366 1440 1576 1784 768 771 781 798 -hsync +vsync
> xrandr --verbose --addmode Virtual1 "1366x768"

Note that this apparently works at the screen level, but I presume the resolutions you mentioned were just that, not the union of resolutions of both screens. I also don't know how to obtain the various numbers other than by querying xrandr on a system that does recognise the resolution you're looking for. 

R.