Model Anatomy See what's inside open-weight AI models

Can I run gpt-oss-20b on a Mac with 64 GB?

Yes

Its published weights (13.8 GB) fit in the 48.0 GB a Mac with 64 GB can use, with room for ≈ 128K tokens of context.

Full analysis of gpt-oss-20b Everything that runs on Mac with 64 GB Get the weights on Hugging Face
hf download openai/gpt-oss-20b

Files and context on Mac with 64 GB

Each file of gpt-oss-20b (and of GGUF versions the site has analyzed), and how much context fits next to it, with the context cache in 16-bit or 8-bit.

FileSizeOn Mac with 64 GB Context (16-bit)Context (8-bit)
As published13.8 GBFits128K128K
4-bit (estimate)11.8 GBFits128K128K

gpt-oss-20b on other hardware

Popular models that run on Mac with 64 GB

Assumes 75% of the Mac's memory is usable (macOS's default limit for the GPU; it can be raised) and at least 4K tokens of context for one conversation, with the context cache in 16-bit unless noted. Fits leaves at least 20% of that memory for context; Tight leaves less.