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

Yes, just

Its published weights (41.3 GB) fit in the 48.0 GB a Mac with 64 GB can use, with room for ≈ 2K tokens of context.

Full analysis of gpt-neox-20b Everything that runs on Mac with 64 GB Get the weights on Hugging Face

hf download EleutherAI/gpt-neox-20b

Files and context on Mac with 64 GB

Each file of gpt-neox-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.

File	Size	On Mac with 64 GB	Context (16-bit)	Context (8-bit)
As published	41.3 GB	Tight	2K	2K
4-bit (estimate)	11.7 GB	Fits	2K	2K

gpt-neox-20b on other hardware

NVIDIA H100Yes
RTX 5090Probably, at 4-bit
RTX 4090Probably, at 4-bit
RTX 3090Probably, at 4-bit
RTX 5060 Ti 16 GBProbably, at 4-bit
RTX 3060 12 GBNo
RTX 4060No
Mac with 32 GBProbably, at 4-bit
Mac with 64 GBYes, just
Mac with 128 GBYes

Popular models that run on Mac with 64 GB

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Qwen3-8BQwen · 8.19B
Qwen3-Coder-30B-A3B-Instruct-GGUFunsloth · 30.5B
Qwen3.6-35B-A3B-FP8Qwen · 36.0B
Qwen2.5-7B-InstructQwen · 7.62B

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.