“Linux Vulkan Performance + Exile Exchange 2 interaction (RX 6600 + KDE/Wayland/X11)”

Hello,

I would like to report persistent performance issues with Path of Exile 2 on Linux after extensive testing across multiple environments.

System:

OS: CachyOS (Arch-based)

GPU: AMD Radeon RX 6600

CPU: Intel Coffee Lake (Z390 platform)

Monitor: 144 Hz

Drivers: Mesa RADV

Vulkan: Working correctly (vulkaninfo confirmed)

Desktop environments tested:

KDE Plasma (X11 and Wayland)

XFCE4 (X11)

Issue summary:
PoE 2 is playable on Linux, but suffers from frequent and severe FPS spikes (down to ~9–15 FPS) during high-density encounters (Rituals, Breach, Abyss, heavy visual effects). The issue becomes significantly worse when using Exile Exchange 2 alongside the game.

What was tested:

X11 vs Wayland sessions

Multiple Steam launch options

Vulkan-only rendering

RADV_PERFTEST=gpl (reduces shader stutter)

Windowed / fullscreen / windowed fullscreen

With and without Exile Exchange 2 running

Observed behavior:

Wayland + RADV_PERFTEST=gpl results in noticeably fewer FPS spikes than X11.

However, when Exile Exchange 2 (Qt AppImage) is used on Wayland, the game frequently shows black screens or broken focus behavior (likely Vulkan swapchain + Qt/Wayland interaction).

On X11, Exile Exchange 2 functions correctly, but performance spikes are much more frequent and severe.

Remaining performance issues appear related to shader compilation, CPU main-thread stalls, and/or asset streaming rather than desktop environment configuration.

Conclusion:
After extensive testing, it appears these performance issues cannot be resolved at the user level and are likely engine-side limitations of PoE 2’s current Linux/Vulkan implementation, especially when interacting with external Qt-based tools such as Exile Exchange 2.

I hope this report and testing effort is useful for tracking Linux and Vulkan performance issues. I can provide additional logs or reproduce specific scenarios if needed.

Thank you for your time.

**Update / additional testing:**

Issue persists consistently during high-density encounters (Abyss / Inscribed Ultimatum) with multiple rare mobs and heavy FX.

**Tested configurations:**
- Vulkan (native) and DirectX 12 via Proton Experimental
- 2560×1440 and 1920×1080
- FSR Quality and NIS upscaling
- KDE Plasma (X11/Wayland) and XFCE4 (X11)

**Observed behavior:**
- Severe frametime spikes and FPS drops to 8–13, fully reproducible
- GPU usage reaches 95–100%
- Multiple CPU cores hit 100%
- Indicates render-thread / FX pipeline stalls rather than simple performance scaling

**Additional notes:**
- Issue occurs even without Exile Exchange running, though overlays/tools make it more visible
- Reproducible across all tested configurations
- Suggests engine-side limitation under FX-heavy content on Linux