Felix Miata wrote:

> What makes you think that?

If you compare the resolution from the first and the second.

Meanwhile (and big thanks to you that you forced me digging into it) I found
what I needed.

First of all the xorg.conf is not that bad - it provides to the X server
exactly what I need. Perhaps modlines and some other stuff can be skipped -
agreed.
Back then when I bought the notebook (it is like 1y ago) I did not have that
much time to dig into that, because of too many reasons.

However now I checked again xrandr and found out the scale-from option

So for example
        xrandr --output eDP1 --scale-from 1920x1080
does exactly what I was missing.

Now I need to find out how I can use the two monitors independent of each
other. I mean when I expand a window it should expand into the range of the
current monitor, the window is in. I'm sure I've had this before.

regards