What display manager/window manager can support multiple monitors with different dpi?

Question

There is no permutation that I have yet found of window manager / display manager, that correctly scales windows and applications on two different monitors with two different DPIs.

I have a 40 inch 4k monitor running about 110 dpi, plugged into a hidpi Dell notebook at about 240dpi. I have to accept far too tiny assets on the hidpi or far too large on the big monitor. It just doesn't look good. Yes there are some "halfway points" that kinda work, and Unity does allow asset scaling separately by monitor to some degree, but I still get problems in applications themselves.

I have tried different combinations of Unity / Gnome 3 / KDE / I3 and even e17. Most of the time display manager (I think) was lightdm, as the distro was usually Ubuntu, but I have tried Fedora 22 also, and Kubuntu which I think use different display managers. Very latest versions each time / clean installs.

All of the time I'm seeing poor scaling effects. I don't mind running beta software. I don't mind some instability. What I do mind is visual inconsistency. Where should I go? Which distro does this well, now?

I'd ideally like all the window manager components and the applications to scale consistency.

Should I wait for Wayland? Can I get it now? Does that solve the problem?

Mir?

I have the same problem, I use kde. Somebody suggested this to me http://unix.stackexchange.com/questions/219058/scaling-the-desktop-kde But it seems dangerous to use with different external screens (as I do). Would love an automatic config utility. I just end up working on one monitor now. — dorien, Dec 17 '15 at 11:48

score 2 · Answer 1 · answered Dec 21 '15 at 09:01

2

If I'm not wrong you cannot do that with Xorg. It would only be possible with Wayland.

You could try latest Plasma (development branch, not the released one): https://dot.kde.org/2015/12/18/first-plasma-wayland-live-image

answered Dec 21 '15 at 09:01

Andrea Scarpino

159

You can use xrandr --scale option. See: https://askubuntu.com/a/555812/1841 – kravemir Jun 08 '17 at 17:52

jsquaredz · Answer 2 · 2015-12-23T16:18:21.973

Wayland promises to offer High DPI support like what you are talking about. Only issue I have with Wayland is that it is still not fully baked.

I have run it on my Fedora 23 Gnome install and its great except when it doesn't work. For instance Gparted wont start because GTK cant open display 0, etc. Anyway its not too far off, and it looks like they are hard at work going through the bug list.

Maybe in a year we will have decent wayland (i.e. high dpi multi monitor) support.

http://fedoramagazine.org/update-wayland-support-fedora-23/

eddygeek · Accepted Answer · 2016-08-02T09:03:18.253

2

IIRC neither gnome nor kde currently support dpi scaling on wayland, so the answer is currently none.

Update: Work has started on multi-DPI in Gnome 3, no indication yet on whether it would be usable in 3.22...

edited Aug 02 '16 at 09:03

answered Feb 11 '16 at 17:08

eddygeek

1,291

It should be added though, Gnome doesn't even support point scaling while KDE does. So basically Gnome can do 1 to 2 times scaling, but can't do 1.5 times scaling. I think they are attempting to fix that, but yeah. – Goddard Sep 08 '17 at 00:19

wvengen · Answer 4 · 2016-12-12T22:45:13.523

2

When calling xrandr, you can add --scale 2x2 for the non-HiDPI output. This will render the display image in high resolution, but scale it down before displaying it on the monitor. It's doesn't always look pretty, but it's usable. For example, I'm extending my internal 2560x1600 retina display eDP-1 with an external non-HiDPI monitor DP-1:

#!/bin/sh
EXT=`xrandr --current | sed 's/^\(.*\) connected.*$/\1/p;d' | grep -v ^eDP`
xrandr --output eDP-1 --auto --pos $(((3840-2560)/2))x2400 --scale 1x1 \
       --output "$EXT" --auto --scale 2x2 --pos 0x0

What display manager/window manager can support multiple monitors with different dpi?

4 Answers4