OpenAI
Can the Ryzen AI Max+ 395 (128 GB) run gpt-oss 120B?
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Yes. gpt-oss 120B is a 65 GB download (MXFP4 (as shipped)). The Ryzen AI Max+ 395 (128 GB) gives the GPU 96 GB, leaving about 31 GB for context and runtime (our arithmetic).
Does it fit?
| gpt-oss 120B memory | 65 GB at MXFP4 (as shipped) (Ollama: gpt-oss tags) |
|---|---|
| Ryzen AI Max+ 395 (128 GB) GPU memory | 128 GB unified memory, of which AMD says up to 96 GB can be dedicated graphics memory through Variable Graphics Memory. We use 96 GB for fit. (AMD) |
| Left over | About 31 GB (our arithmetic) |
| Verdict | Fits 4 GB or more to spare (our estimate bands) |
Recommended quantization and context
Use the MXFP4 (as shipped) build that Ollama's tag downloads; the memory figure above is for that build. The model supports up to 128K of context, but longer context uses more memory. Ollama starts at a 4096-token context by default (Ollama FAQ).
With about 31 GB spare you have room to raise the context. Raise it in steps and re-check with ollama ps.
On this mini PC the GPU's share of memory depends on settings. On Windows, set Variable Graphics Memory in AMD Software (Performance, then Tuning); on Linux, see AMD's ROCm notes on BIOS VRAM and GTT. Details are in the install guide.
Run it
ollama run gpt-oss:120bThen check it's on the GPU:
ollama psThe PROCESSOR column should read 100% GPU. Driver setup for AMD cards on Windows, Linux and macOS, plus common fixes, is in the install and run section.
Where to buy the Ryzen AI Max+ 395 (128 GB)
Minisforum MS-S1 MAX 128GB / 2TB (Ryzen AI Max+ 395)
$3,919 Minisforum · checked Oct 27, 2026, 12:40 PM CT
Caveat
Store data says estimated shipping late November. The 128GB / 4TB version was $4,199.
Check price at Minisforum (opens in a new tab)
GMKtec EVO-X2 128GB / 2TB
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Sold at Amazon.
Check price at Amazon (opens in a new tab)FAQ
Can the Ryzen AI Max+ 395 (128 GB) run gpt-oss 120B?
Yes: gpt-oss 120B needs 65 GB (MXFP4 (as shipped), Ollama library) and the Ryzen AI Max+ 395 (128 GB) gives the GPU 96 GB, leaving about 31 GB. That leaves room to raise the context above the 4096-token default. The fit bands are our estimate.
How much VRAM does gpt-oss 120B need?
65 GB for the MXFP4 (as shipped) build in the Ollama library, plus roughly 1–4 GB for context and runtime (our estimate). See the 96 GB page for other models that fit.
What command runs gpt-oss 120B?
ollama run gpt-oss:120b. Then run "ollama ps" and check the PROCESSOR column reads 100% GPU.
How fast is gpt-oss 120B on the Ryzen AI Max+ 395 (128 GB)?
We don't list a speed because we have no sourced measurement for this pairing. Speed depends on memory bandwidth, quantization and context length.