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OpenAI gpt-oss 120B (MoE) Target: AMD Ryzen AI Max+ 395 Strix Halo 128GB

Can I Run OpenAI gpt-oss 120B on AMD Strix Halo 128GB? Unified Memory Benchmark

Required VRAM (8k Q4)
71.17 GB

Model weights, initial KV-cache, and CUDA context buffers.

Hardware Headroom
+24.83 GB

Available safety margin for OS compositing and context expansion.

Estimated Speed
~35 tok/s

Throughput determined by memory bus bandwidth.

Hardware Physics & Bottleneck Analysis

Holding 116.8 billion parameters requires an enormous unified memory space. While traditional desktops split memory across two PCIe slots, AMD Strix Halo places 128GB of coherent LPDDR5X-8533 memory directly on the APU substrate (256 GB/s). ROCm and Vulkan can allocate up to 96GB to the integrated GPU, leaving 32GB for the operating system and IDE.

Tier 1 Free Software Optimization ($0)

On Linux, configure the ROCm GTT memory ceiling via kernel boot parameter `amdgpu.gttsize=98304` to grant llama.cpp access to the full 96GB pool, and run `llama-server -fa on -ctk q8_0` for maximum prompt-processing throughput.

Option 1: Sovereign Local Hardware

Buy Hardware on Amazon

Direct Prime-badged hardware accessories and GPUs with dynamic regional routing.

Option 2: Cloud Rental (On-Demand)

Rent Cloud GPUs on RunPod & Vast.ai

If local memory falls short, deploy multi-GPU pods from $0.35/hr with zero commitment.

Frequently Asked Questions

Why does Dual RTX 3090 48GB fail on gpt-oss 120B?

Dual RTX 3090 provides 48GB VRAM total. At Q4_K_M, gpt-oss 120B requires 71.17 GB—exceeding 48GB by 23.17 GB. Offloading those 23 GB to DDR5 system RAM over PCIe cuts speed from 35 tok/s down to 1.8 tok/s.

Does Strix Halo 128GB get noisy when running 120B models?

No. The total system TDP is only 85W–120W, operating whisper-quiet in compact mini-PC chassis compared to 750W dual-GPU desktop rigs.

Calculate Exact Context Window Headroom

Explore live token throughput and VRAM allocation sliders in the interactive matchmaker.

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