Quick verdict: vLLM does not work reliably on Strix Halo
vLLM combined with PyTorch Flash Attention causes GPU hangs on the Radeon 8060S (gfx1151). The TheRock PyTorch builds that target this GPU are incompatible with vLLM’s CUDA-origin code paths, and the eager-mode workaround breaks tool calling. Community reports consistently confirm this across multiple kernel and ROCm versions. Use one of these alternatives instead:Why vLLM fails
Strix Halo’s iGPU is gfx1151 (RDNA 3.5). vLLM was designed for NVIDIA CUDA GPUs and later gained ROCm support for datacenter AMD GPUs (MI250, MI300X). The consumer iGPU in Strix Halo sits outside that supported matrix. The failure chain:- PyTorch TheRock builds — AMD ships TheRock builds for gfx1151, but these builds interact poorly with vLLM’s Flash Attention implementation.
- Flash Attention + vLLM = GPU hang — when vLLM enables Flash Attention on gfx1151, the GPU hangs and the system becomes unresponsive, requiring a hard power cycle.
- Eager mode workaround — disabling Flash Attention avoids the hang, but throughput drops significantly and tool calling breaks entirely.
- Tool calls broken on AMD — even in eager mode, vLLM’s tool calling parser fails on AMD ROCm, which rules out coding agent use.
Recommended alternative: llama.cpp with Vulkan
llama.cpp compiled with the Vulkan backend is the most reliable and fastest option on Strix Halo. Vulkan delivers 21% faster token generation than ROCm on this hardware and works on both Linux and Windows.
Prerequisites
- A Strix Halo system with 128GB unified memory
- Vulkan drivers installed (included in Mesa on Linux, Adrenalin on Windows)
cmake,gcc/clang, andgit
Build llama.cpp with Vulkan
Launch the server
-ngl 999 flag offloads all layers to the GPU. Verify the server responds:
Alternative: Ollama (pin to 0.17.7)
Ollama is the easiest path if you wantollama run simplicity. You must pin version 0.17.7 — all 0.18.x versions have a GPU detection regression on Strix Halo that causes Ollama to fall back to CPU-only inference.
Install and pin Ollama 0.17.7
Run a model
Workaround: vLLM eager mode (partial, not recommended)
If you have a specific reason to need vLLM’s API shape exactly, you can try eager mode. Expect degraded throughput and broken tool calling.- No Flash Attention — throughput is significantly lower than working setups
- Tool calls broken — the structured output parser fails on AMD
- Context length limited — memory pressure builds fast without paged attention
- GPU hangs still possible — long contexts can still trigger hangs
Backend comparison summary
Expose your model via Tokios
Once you have a working runtime (llama.cpp or Ollama), run the Tokios connector next to it. The connector dials out to https://api.tokios.com — no inbound ports on your box — and gives you a single authenticated endpoint.
If you are buying hardware today
Strix Halo’s 128GB unified memory sounds compelling on paper, but the software ecosystem is fragile. For reliable local LLM inference:
Any of these will give you a smoother experience than Strix Halo for the same or less effort.
Next steps
Strix Halo model compatibility
Which models fit in 128GB and at what quantization.
Strix Halo use case
Full connector pairing walkthrough for Strix Halo.
DGX Spark use case
The recommended alternative with 128GB unified memory.
vLLM remote access
Expose vLLM on supported NVIDIA hardware securely.