Arch Linux + Hyprland on GPD Win4 with iGPU + eGPU

Document Objective

Written for the GPD Win4’s two AMD GPUs (iGPU + eGPU) on Arch Linux + hyprland.lua, offloading rendering onto the eGPU — but the approach generalizes, so it also serves as a reference for external-GPU setups on other hardware.

• Configuration guidance (iGPU only / with eGPU) — Hardware Stack
• Self-check commands to verify current state — Verification
• All relevant commands in one place — distributed across sections
• Tweak log: what’s applied, what’s proposed — Current State / Proposed
• Searchable wiki for later reference — the whole doc

The objective doubles as the document structure: each bullet maps to a section below, in reading order.

Hardware Stack

• OS: Arch Linux + Hyprland 0.56.1 (Lua config officially supported)
• 2 AMD GPUs: iGPU (Radeon 780M) + eGPU (RX 7600M XT, via OCULINK)
• BIOS: UMA frame buffer set to 8G (iGPU VRAM; Advanced > CBS > NBIO > GFX Configuration)

1. iGPU Only

• Both built-in and external monitors work
• Disabling any monitor works
• Single iGPU is primary

2. With eGPU

@startuml
skinparam componentStyle rectangle

package "GPD Win4" {
    component "iGPU\nRadeon 780M" as igpu
}
component "eGPU\nRX 7600M XT" as egpu
component "External Monitor" as monitor

igpu --> egpu : OCULINK (PCIe)
egpu --> monitor : HDMI
@enduml

Expected:

• Turn on eGPU before powering on the machine
• Both monitors work
• iGPU is primary
• Run apps on the eGPU via command line

Verification (quick self-check, run first)

lspci | grep -i 7600M                         # eGPU detected? bus id?
# stable offload check (derived id, not DRI_PRIME=1 which is index-relative)
DRI_PRIME="pci-0000_$(lspci | awk '/7600M/{print $1}' | tr '.:' '__')" glxinfo | grep -i renderer  # -> RX 7600M XT
egpu glxinfo | grep -i renderer               # same via wrapper
vulkaninfo --summary                          # both GPUs visible (--list-devices invalid)
hyprctl monitors all                          # active monitors per output
readlink -f ~/.config/hypr/cards/{egpu,igpu}  # symlink targets

Is the eGPU taking workload? While a game runs via egpu <game>, watch GPU busy %:

watch -n 1 'for g in egpu igpu; do n=/sys/class/drm/$(basename "$(readlink -f ~/.config/hypr/cards/$g)"); echo "$g: $(cat "$n/device/gpu_busy_percent")%"; done'

If the eGPU line is high (90%+ in a real game) while iGPU stays low, the eGPU is doing the work. Richer view (already installed): amdgpu_top or amdgpu_top --smi.

Example — a Steam game running on the eGPU (eGPU busy ~25%):

Verified Hardware Mapping (Aug 2026, this boot)

• eDP-1 (GPD G1618-04) on iGPU; HDMI-A-1 (AOC AG322QWG3R3) on eGPU — both already work with the eGPU attached.

IDs are per-boot snapshots, not promises. cardN/renderD* and even PCI bus IDs can change randomly between reboots. Always resolve dynamically (lspci, /dev/dri/by-path/) or use the symlinks ~/.config/hypr/cards/{egpu,igpu}.

Verified evidence: in 3 of 8 boot logs the iGPU appeared at 63:00.0 (eGPU absent) instead of 66:00.0. eGPU-present boots have been consistently 03:00.0/66:00.0.

Regenerate the table (verified):

for c in /dev/dri/by-path/pci-*-card; do
    pci=$(basename "${c%-card}"); pci=${pci#pci-0000:}
    card=$(basename "$(readlink -f "$c")")
    render=$(basename "$(readlink -f "${c%-card}-render")")
    dev=$(lspci -nn -s "0000:$pci")
    vid=$(grep -oE '\[[0-9a-f]{4}:[0-9a-f]{4}\]' <<<"$dev" | tr -d '[]')
    name=$(sed -E 's/^[0-9:.]+ //; s/^VGA compatible controller \[0300\]: //; s/ \[[0-9a-f]{4}:[0-9a-f]{4}\] \(rev [0-9a-f]+\)$//' <<<"$dev")
    outs=$(ls -d /sys/class/drm/${card}-* 2>/dev/null | grep -v Writeback | sed "s|.*/${card}-||" | paste -sd,)
    printf "%s | %s | %s | %s / %s | %s\n" "$name" "$pci" "$vid" "$card" "$render" "$outs"
done

Current State (Unchanged)

~/.bashrc has an egpu() launcher — GL-only offload with a hardcoded PCI id:

# egpu
# Custom eGPU launcher shortcut
egpu() {
    if [ -z "$1" ]; then
        echo "Usage: egpu <command>"
        echo "Example: egpu steam"
        return 1
    fi
    echo "Launching $1 on AMD Radeon RX 7600M XT..."
    # Explicitly target the eGPU's unchanging PCI identifier
    env DRI_PRIME="pci-0000_03_00_0" "$@"
}

Verified: egpu glxinfo -> RX 7600M XT; plain glxinfo -> 780M.

How it works: DRI_PRIME=pci-0000_<bus>_<dev>_<func> renders GL/EGL on that GPU only; scanout is Hyprland’s job. Per-command only — desktop stays on iGPU.

Not covered:

1. Vulkan — ignores DRI_PRIME; games enumerate both GPUs themselves.
2. Display driving — compositor decides scanout; already works (see mapping).
3. Hardcoded PCI id — matches now, may drift across boots.

Stable DRM Symlinks (Set Up)

mkdir -p ~/.config/hypr/cards
ln -s /dev/dri/by-path/pci-0000:03:00.0-card  ~/.config/hypr/cards/egpu
ln -s /dev/dri/by-path/pci-0000:66:00.0-card  ~/.config/hypr/cards/igpu

by-path is PCI-stable, so the symlinks survive cardN shifts. Verified: egpu->card1, igpu->card2.

Caveat: igpu (pointing at 66:00.0) dangles in eGPU-absent boots — the iGPU then sits at 63:00.0. Harmless as long as nothing references it.

eGPU Display Ownership (Optional)

Env var for this stack is AQ_DRM_DEVICES (WLR_DRM_DEVICES is gone in Aquamarine 0.14+). In ~/.bash_profile, igpu first = primary:

export AQ_DRM_DEVICES="$HOME/.config/hypr/cards/igpu:$HOME/.config/hypr/cards/egpu"

• Set before Hyprland starts (login shell); effective after logout/login
• Currently unset and monitors already work — only makes ownership deterministic

Proposed egpu() Improvements (Not Applied)

1. Resolve PCI id at call time. lspci emits 03:00.0 with a dot — replace [.:], not just :.

egpu() {
    if [ -z "$1" ]; then
        echo "Usage: egpu <command>"
        echo "Example: egpu steam"
        return 1
    fi
    local id
    id=$(lspci | awk '/7600M/ {print $1}')
    if [ -z "$id" ]; then
        echo "eGPU (RX 7600M XT) not detected" >&2
        return 1
    fi
    env DRI_PRIME="pci-0000_${id//[.:]/_}" "$@"
}

Pros: no stale id, clear “not detected” error. Cons: one lspci call per run.

2. Vulkan offload. MESA_VK_DEVICE_SELECT=1002:7480 (layer installed). Verified: reorders eGPU to GPU0 but does not hide the other GPU. Helps apps defaulting to the first adapter; name-picking apps unaffected.

Open Questions (decided)

• Is 03:00.0 stable? Stable in all eGPU-present boots (5/5); iGPU moves to 63:00.0 when eGPU absent. Dynamic resolution stays as the safe default.
• MESA_VK_DEVICE_SELECT in egpu()? Optional nice-to-have — only helps Vulkan games without an in-game adapter picker. Not required.
• Rename egpu? Cosmetic only; keeping it is fine.
• Enable AQ_DRM_DEVICES? No — everything works, and the igpu symlink dangles in eGPU-absent boots, so enabling it adds risk with no current benefit.