Physical setup

flowchart LR
    A[Laptop Latitute 7390] <-->|TB3 60W| B[eGPU TH3P4G3]
    B -->|PCIe| C[AMD XFX RX 590 Fatboy]
    B -->|TB3| D[OWC Thunderbolt Dock]
    D -->|TB| E[Monitor 1]
    D -->|TB| F[Monitor 2]
    D -->|Ethernet| G[Internet]
    D -->|USB| H[Keyboard]
    E -->|internal USB hub| I[Audio DAC]

Software setup

• Manjaro Linux
• Cinnamon (X11)

Drivers

Package: xf86-video-amdgpu

For hashcat:

• Requires ROCm: -> RX 590 needs PCIe atomics support -> TH3P4G3 does not support atomics
• Working with proprietary opencl-legacy-amdgpu-pro: -> Bug eGPU duplicated: clinfo -l -> Hashcat working (way faster than with iGPU)

Tests

I have tested:

• X11 on eGPU + Gaming on eGPU -> Lag
• X11 on eGPU + Gaming on iGPU -> Lag
• X11 on iGPU + Gaming on iGPU -> Okay
• X11 on iGPU + Gaming on eGPU -> Good

Better to leave integrated GPU manage X11 and start apps on explicitly on external GPU (see PRIME)

Notes:

• Hot-plug: Yes (kernel 5.14+). Works with dock + monitors. Can run Apps on eGPU using PRIME
• Hot-unplug: Not supported. Doing so will produce errors in dmesg and logout. Avoid: Freeze if hot-plug again. relevant: https://gitlab.freedesktop.org/drm/amd/-/issues/1081

For additional issues X11 on iGPU, see https://wiki.archlinux.org/title/External_GPU#Known_issues_with_eGPUs_on_Xorg