Can the Mac Mini M4 run gpt-oss-20b?

Just. gpt-oss-20b at Q4_K_M needs about 13.8 GB of the Mac Mini M4's 16 GB, running at an estimated 23 tok/s. Keep context short and close other GPU apps.

Memory
16 GB
Needs at Q4
13.8 GB
Headroom
2.2 GB
Speed (Q4_K_M)
~23 tok/s

Every quantization

gpt-oss-20b (21.5B, 3.6B active) on 16 GB

QuantWeightsNeedsFitEst. speed
Q4_K_M12 GB13.8 GBTight~23 tok/s
Q5_K_M15 GB16.8 GBToo big -
Q8_023 GB24.8 GBToo big -
FP1643 GB44.8 GBToo big -

Estimates. Needs = weights + 1.8 GB for KV cache and runtime at modest context. Speed is single-stream decode scaled from the Mac Mini M4's 120 GB/s bandwidth (Estimated from memory bandwidth (llama.cpp decode)). Long contexts need more memory and run slower.

Run it

Copy, paste, go

llama-server -hf unsloth/gpt-oss-20b-GGUF -ngl 99

Ollama pulls a Q4 build by default. Pick a larger quant only if the table above says it fits. Full gpt-oss-20b details →

Compare

Same model, other hardware - and other models on this card

gpt-oss-20b on other hardware

Also runs on the Mac Mini M4

Frequently asked

Quick answers

Can the Apple Mac Mini M4 run gpt-oss-20b?

Just. gpt-oss-20b at Q4_K_M needs about 13.8 GB of the Mac Mini M4's 16 GB, running at an estimated 23 tok/s. Keep context short and close other GPU apps.

How much VRAM does gpt-oss-20b need?

About 12 GB of weights at Q4_K_M, 23 GB at Q8_0 and 43 GB at FP16. Add roughly 1.8 GB for the KV cache and runtime at modest context lengths.

How fast is gpt-oss-20b on the Mac Mini M4?

Roughly 23 tokens per second at Q4_K_M (single user, llama.cpp-style decode). This is an estimate from the Mac Mini M4's 120 GB/s memory bandwidth; as a mixture-of-experts model only about 3.6B parameters are read per token, which is why it is faster than its size suggests.