How fast will GPT-OSS 20B feel on the AMD Ryzen AI Max+ 395 128GB (Strix Halo)?

GPT-OSS 20B on the AMD Ryzen AI Max+ 395 128GB (Strix Halo)

GPT-OSS 20B is a 20.91B-parameter mixture-of-experts model (3.6B active per token). At MXFP4 it needs about 12.9 GB of memory. The AMD Ryzen AI Max+ 395 128GB (Strix Halo) has 119 GB usable, so it fits entirely in memory. Expect about 74 tokens/sec (65–82), with the first token after 0.3 s for a short prompt. This estimate is based on community benchmarks of this exact setup.

Speed by quantization

QuantizationFile sizeMemoryGenerationFirst tokenSource
MXFP412.1 GBFits74 tok/s0.3 sMeasured

GPT-OSS 20B on other hardware

Other models on the AMD Ryzen AI Max+ 395 128GB (Strix Halo)

All models on the AMD Ryzen AI Max+ 395 128GB (Strix Halo) · GPT-OSS 20B on all hardware

Estimates for a short prompt on a single device. Measured numbers come from community benchmarks (r/LocalLLaMA, localscore.ai and more); others are derived from similar setups or projected from specs. Open source on GitHub.