How fast will GPT-OSS 120B feel on the MacBook M2 Pro 16GB?

GPT-OSS 120B on the MacBook M2 Pro 16GB

GPT-OSS 120B is a 116.83B-parameter mixture-of-experts model (5.1B active per token). At MXFP4 it needs about 64.1 GB of memory. The MacBook M2 Pro 16GB has 12 GB usable, so it doesn't fit, even at its smallest quantization.

Speed by quantization

QuantizationFile sizeMemoryGenerationFirst tokenSource
MXFP463.4 GBDoesn't fitWon't run——

GPT-OSS 120B on other hardware

Other models on the MacBook M2 Pro 16GB

All models on the MacBook M2 Pro 16GB · GPT-OSS 120B 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.