So I've got this new eGPU and it works fine. But Steam Client has issues with it.

Your system information

• Steam client version (build number or date):

Version bêta de Steam:  Version stable
Version de Steam:  1759461205
Date du build du client Steam:  ven. 3 oct. 4:27 UTC - 08:00
Date du build de la version Web de Steam:  jeu. 2 oct. 20:12 UTC - 08:00
Version de l'API Steam:  SteamClient023

(installed from the RPM Fusion repo)

• Distribution : Fedora Linux 43 WorkStation Edition

• Opted into Steam client beta?: No

• Have you checked for system updates?: Yes

• Steam Logs:
  steam-logs.tar.gz

• GPU:
  From the steam command line output :

Response: gpu_topology {
  gpus {
    id: 1
    name: "AMD Radeon 780M Graphics (RADV PHOENIX)"
    vram_size_bytes: 13995606016
    driver_id: k_EGpuDriverId_MesaRadv
    driver_version_major: 25
    driver_version_minor: 2
    driver_version_patch: 5
    luid: 0
  }
  gpus {
    id: 2
    name: "AMD Radeon RX 7600M XT (RADV NAVI33)"
    vram_size_bytes: 8589934592
    driver_id: k_EGpuDriverId_MesaRadv
    driver_version_major: 25
    driver_version_minor: 2
    driver_version_patch: 5
    luid: 0
  }
  gpus {
    id: 3
    name: "llvmpipe (LLVM 21.1.2, 256 bits)"
    vram_size_bytes: 3221225472
    driver_id: k_EGpuDriverId_MesaLLVMPipe
    driver_version_major: 25
    driver_version_minor: 2
    driver_version_patch: 5
    luid: 0
  }
  default_gpu_id: 1
}

From lspci -k -d ::03xx :

0b:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Navi 33 [Radeon RX 7600/7600 XT/7600M XT/7600S/7700S / PRO W7600] (rev c7)
	Subsystem: Device 2014:8014
	Kernel driver in use: amdgpu
	Kernel modules: amdgpu
64:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Phoenix1 (rev dd)
	Subsystem: Lenovo Device 50d9
	Kernel driver in use: amdgpu
	Kernel modules: amdgpu

=> So, Radeon 780M from the Ryzen + Radeon RX 7600M XT (eGPU)

Please describe your issue in as much detail as possible:

Main UI loops/crashes after clicking the Steam icon. Details below.

Steps for reproducing this issue:

1. Start the computer with eGPU connected, login
2. Clic the Steam icon in the dash bar (I suppose it points to /usr/share/applications/steam.desktop)
3. The client then loops trying to start again and again.

What is expected

Steam should start when I left-clic on the icon.

How to bypass the issue

• [FAILURE] I tried to tickle/edit steam.desktop file (targeted option : PrefersNonDefaultGPU=true)
• [SUCCESS] launching the steam client from the terminal works
• [SUCCESS] launching the steam client with a right-clic on the Steam icon and choosing the option to use discrete GPU to start the app works
• [SUCCESS] opting out the GPU rendering for the web client in steam options works (i can use a simple left-clic on the icon this way)

Hardware setup - important (?) note

Laptop --> TB4 link --> Dock --> TB3/4 link --> eGPU --> HDMI link --> secondary screen.

The Steam client main UI wants to start on the secondary screen (login UI works and happens on primary/integrated screen) and i don't know how to change the default screen on which the main UI should appear, if I can do that, if it would change anything at all.

As a passing note, while looking into this issue I noted that in each (working) case Steam is using ~400% CPU just sitting there (process : fossilize_replay) which sounds like a suboptimal use of hardware resources. Never looked before so I cannot tell if that was the case before I got the eGPU.