KDE/Wayland/AMD APU - Is It Possible To Scale Two Screens At Different Values?

[abc123]

Hi,

On Manjaro KDE Plasma fully updated on a fairly new Mini PC.
I am running Wayland with an AMD APU.
I have two screens: one small 4K monitor and one large 50 inch 4K TV.
Monitor is connected via Display Port and TV is connected via HDMI.
(both monitor and TV are set at 1080p and the monitor is the main display)

I wish to scale each screen above with different values.
100% scale for monitor and 200% scale for TV.
I played around with the display settings, but could not get it to work.

Anyone know how to do the above, thank you!
(this is my very first time using Wayland)

Jesse

[deroberts1]

It is possible using xrandr. At least that is how I have done it. I have an external monitor attached to an old Dell with an Nvidia chip. Here is what is in my old xrandr script looked like:

xrandr --output LVDS-1 --gamma 2.00:2.0:2.00 (the laptop)
xrandr --output VGA-1 --gamma 1.45:1.50:1.66 (the external monitor)

That said. after much fiddling I one day got my external monitor configured the way I like using its own screen controls. The lappy got adjusted using KDE.

Good luck.

[Mirdarthos]

Seeing as you asked about Wayland specifically, I recommend you look at wlr-randr. From the man page:

Command line interface which allows setting the size, scale, orientation of the output for a screen. This utility requires the compositor to implement the wlr-output-management protocol.

It’s available from the extra repository:

$ pamac search wlr-randr
[...]
wlr-randr  0.5.0-1                                                                                                                                                                                                         extra
Utility to manage outputs of a Wayland compositor

So can be installed using:

pamac install wlr-randr

[Tomek]

It should be perfectly possible. Simply go to System settings → Display & Monitor and adjust scale settings as you wish.

[BG405]

This is indeed the case on my system; I just checked and the scaling can be set independently for each display.

[soundofthunder]

@abc123

I wish to scale each screen above with different values.

@BG405

This is indeed the case on my system; I just checked and the scaling can be set independently for each display.

Indeed, this is possible via the GUI, when using Wayland – X11 isn’t quite as versatile in that regard.

[tracyanne]

@abc123

I wish to scale each screen above with different values.
100% scale for monitor and 200% scale for TV.
I played around with the display settings, but could not get it to work.

In a word Yes.

It is certainly possible on my Recording studio Computer with an nVidia Card. where I have the a 1920 by 1080 monitor at 100% and the laptop screen at 85%.

As @BG405 points out via the GUI.

KDE System Settings → Display & Monitor

Select the Monitor you want from the drop down box, then set it’s scaling. Then click on the Apply button and the Keep button when the confirm settings window appears.

[abc123]

Sorry, I forgot to mention that the TV is a replica of the monitor (monitor is primary)

[BG405]

This is probably the issue. If you’re “mirroring” the displays then I’d assume the scaling has to be the same on both.

[scotty65]

@Mirdarthos

Seeing as you asked about Wayland specifically, I recommend you look at wlr-randr

wlr-randr won’t work for Plasma Wayland as KWin isn’t a wlroots compositor:

wlr-randr  
compositor doesn't support wlr-output-management-unstable-v1

The same applies for the AUR’s wlr-randr-git package.

KDE developer Nate Graham explained why Plasma Wayland does not use wlroots a couple of years ago in this blog post:

In addition, the problem of fragmentation of effort is being solved by wlroots, a library of Wayland implementations that you can use to build a Wayland compositor. We don’t use it in KDE’s KWin compositor because we already did most of that work ourselves before wlroots existed, but it’s a big benefit to anyone writing a new compositor from scratch today.

[abc123]

Ok, I got everything working now. Thank you!

[soundofthunder]

For the sake of selecting the right post as a solution, or making this topic remotely useful to others, please explain exactly what you did for everything to be working now. Thanks.

[abc123]

Sorry, I turned off the duplication of monitor on the TV.
I was then able to individually change the zoom on the TV.
I also had to add a default panel to the TV screen.

[soundofthunder]

Thankyou.

As you discovered all this yourself, marking your own post as the solution is valid. Please do that to allow others to easily find it and for the topic to close automatically.

Regards.