Can not configure external monitor with eGPU in Gamemode

Hi,

I’m using an eGPU with my ROG Ally X running the Bazzite GNOME version. Everything works perfectly in desktop mode—the eGPU is correctly detected, and the session is displayed on the monitor connected via HDMI.

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  %%%%%%%%%    %%%%%%%%%%%%%%%%           󰣛  Bazzite 42 (FROM Fedora Silverblu)
  %%%%%%%%%    %%%%%%%%%%%%%%%###           Linux 6.14.4-103.bazzite.fc42.x864
  %%%%%%%%%    %%%%%%%%%%%%%######        󰅐  10 mins
  ==                  =======######  
  ==                  =========#####      󰾰  ROG Ally X RC72LA_RC72LA (1.0)
  %%%%%%%%%    %%%%%%%####======#####     󰻠  AMD Ryzen Z1 Extreme (16) @ 5.13 z
  %%%%%%%%%    %%%%%#######=====#####     󰍛  AMD Radeon RX 5700 XT [Discrete]
  %%%%%%%%%    %%%#########=====#####     󰍛  AMD Phoenix1 [Integrated]
  %%%%%%%%%    %%##########=====#####       7.51 GiB / 15.31 GiB (49%)
  %%%%%%%%%====###########=====######       32.96 MiB / 32.96 MiB (100%) - ov]
   %%%%%%%%====#########======######        2.01 TiB / 3.43 TiB (58%) - btrfs]
    %%%%%%%=====#####========######       󰍹  2560x1440 @ 60 Hz in 27" [Externa]
     %%%%###===============#######          82% [AC Connected]
      %#######==========#########         󰖺  Microsoft X-Box 360 pad 0
        #######################           󰖺  ASUSTeK Computer Inc. N-KEY Device
          ###################             󰖺  Handheld Daemon Controller
              ###########            
                                          󰕮  GNOME 48.1
                                            Mutter (Wayland)
                                            bash 5.2.37
                                            Ptyxis 48.1
                                          󰏖  2679 (rpm), 75 (flatpak)

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I’m following this guide to route my session output through the HDMI-2 port by adding the following to my config:

~/.config/environment.d/10-gamescope-session.conf
OUTPUT_CONNECTOR='HDMI-2'

My gnome-randr gives me:

supports-mirroring: true
layout-mode: logical
supports-changing-layout-mode: true
global-scale-required: false

logical monitor 0:
x: 0, y: 0, scale: 1, rotation: normal, primary: yes
associated physical monitors:
	HDMI-2 ACI ASUS MG279 0x000166c6

HDMI-2 ACI ASUS MG279 0x000166c6
              2560x1440@59.961	2560x1440 	59.96     	[x1.00+, x1.25, x1.50, x1.76, x2.00, x2.25, x2.50, x2.76, x3.02]
              2560x1440@59.951	2560x1440 	59.95*+   	[x1.00+, x1.25, x1.50, x1.76, x2.00, x2.25, x2.50, x2.76, x3.02]
             2048x1152@119.907	2048x1152 	119.91    	[x1.00+, x1.24, x1.51, x1.75, x2.00, x2.25]
[...]
min-refresh-rate: 50
is-for-lease: false
is-underscanning: false
supported-color-modes: [0]
display-name: "Ancor Communications Inc 27\""

eDP-1 TMX TL070FVXS01-0 0x00000000
         1920x1080@119.999+vrr	1920x1080 	120.00+   	[x1.00+, x1.25, x1.50, x1.74, x2.00, x2.31]
             1920x1080@119.999	1920x1080 	120.00    	[x1.00+, x1.25, x1.50, x1.74, x2.00, x2.31]
[...]

However, when I reboot into Game Mode, nothing is displayed on the HDMI-2 output. Gamescope shows that the eGPU is being used, but the image remains on the built-in ROG Ally X screen.

Has anyone encountered this before or knows how to resolve it? Any help would be greatly appreciated!

I suggest you delete the environment.d file and use all-ways-egpu instead

Thanks for this suggestion.

I already had all-the-way-egpu installed. I have deleted environment.d directory (and not file? I guess this was normal) and came to the same issue.

With all-the-way-egpu I have used method 2 and 3.

Was that the right way to do it?

Yes. Method 1 is not working with gamescope