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 3060 12GB has 11 GB usable, so it only fits with part of the model offloaded to system RAM, which slows it down. Expect about 58 tokens/sec (22–94), with the first token after 1.2 s for a short prompt. This estimate is projected from the hardware specs; no benchmarks exist yet.
| Quantization | File size | Memory | Generation | First token | Source |
|---|---|---|---|---|---|
| MXFP4 | 12.1 GB | Partial offload | 58 tok/s | 1.2 s | Projected |
All models on the NVIDIA RTX 3060 12GB · 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.