Gnome - single-display mode is unavailable (two screens)

Ask Fedora
1

I have a 60Hz computer monitor and a projector with 24Hz support (Optoma UHD40) — I run the devices at different refresh rates (60 and 24Hz, or specifically 23.98Hz) and I’m only given an option to ‘join’ or ‘mirror’ the displays:

538b1ba09252abf30bb91825785cbf13f4ca61b8.png
538b1ba09252abf30bb91825785cbf13f4ca61b8.png657×629 11 KB

‘join’ has to be selected in order to getting access to refresh rate options

askubuntu.com implies that the single-display option has been around at least since Gnome 40.4.0:

68d8f89c7008cf95fbe0e1c428b69fca96fb3934.png
68d8f89c7008cf95fbe0e1c428b69fca96fb3934.png1032×869 66.7 KB

6e01e9359cceb81d3c43b00bc424901bc0defa3f.png

another screenshot

I don’t have any need to output to several displays at once since I only ever focus on and view one at a time. This configuration may be a major potential source of errors — after some testing it appears that mpv drops frames with 23.976fps content (24p) if both devices aren’t set to run at 60Hz. The --video-sync=display-resample option also appears to suffer from major performance issues, and was mostly fine after disconnecting the monitor.

In short, please show how to set up (“force” if required) a single-display mode in Gnome and speculate why the mode may not be available to me.

Fedora 36, Gnome…

$ cat /usr/share/gnome/gnome-version.xml:

<gnome-version>
 <platform>42</platform>
 <minor>2</minor>
 <micro>0</micro>
 <distributor>GNOME.Org</distributor>
 <date>2022-06-03</date>
</gnome-version>
2

Single mode was removed, display: Remove SINGLE mode (06caebd0) · Commits · GNOME / Settings · GitLab

0ca982538e4bc1fd02896b9bc0c688b173eb6749.png

Under Displays → Select the monitor you don’t want to use and turn it off.

1 Like
3

Is there change that the displays can be toggled (on/off) from the command-line? This would allow creating a hotkey to save same time and effort.

Otherwise getting another “HTPC” system seems more convenient — would help with the limited amount of HDMI/DP ports and I could strain the main system more freely. I may install Windows for HDR support.

4

The calls are made via dbus, Change scaling/resolution of primary monitor from bash/terminal - #10 by ankursinha

Based on that thread I’m not sure how difficult it would be.

There were also a few projects trying to implement xrandr function for gnome-wayland but I’m not sure how well or if they work. I think gnome-randr was one.