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 NVIDIA RTX PRO 6000 96GB has 89 GB usable, so it fits entirely in memory. Expect about 347 tokens/sec (126–567), with the first token after 0.3 s for a short prompt. This estimate is interpolated from benchmarks of similar setups.
| Quantization | File size | Memory | Generation | First token | Source |
|---|---|---|---|---|---|
| MXFP4 | 12.1 GB | Fits | 347 tok/s | 0.3 s | Derived |
All models on the NVIDIA RTX PRO 6000 96GB · 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.