Home / Can I run it? / gpt-oss-20b / gpt-oss-20b on a Mac mini 24GB

Yes. gpt-oss-20b at Q4_K_M needs about 15.6 GB, and the Mac mini M6 24GB has 18.0 GB usable at a ~4k context.

Can I run gpt-oss-20b on a Mac mini 24GB?

gpt-oss-20b at Q4_K_M needs about 15.6 GB, and the Mac mini M6 24GB has 18.0 GB usable. That figure is 24 GB of unified memory on the spec sheet, of which 18.0 GB is usable for weights and cache, at 170 GB/s memory bandwidth. OpenAI’s open 20B-class gpt-oss model. Only a few billion parameters are active per token, so decode can be quicker than a dense 20B. These are estimates from our formula, not measured benchmarks.

Quant that fits

Q4_K_M Fits with headroom

Memory needed

15.6 GB at Q4_K_M, ~4k context

Usable unified memory

18.0 GB of 24 GB unified memory

Est. tokens/sec

up to 62 estimate

gpt-oss-20b · Mac mini M6 24GB · Everything this machine runs · Q4 vs Q8 vs FP16

Memory at each quant

Estimated tokens per second

Estimate: up to 62 tokens/sec at Q4_K_M (upper bound: this is a Mixture-of-Experts, and only the active weights are counted). This is a bandwidth-derived range, not a bench. Efficiency is a 45–80% unified-memory band from How we calculate.

Context headroom

At Q4_K_M, this machine has headroom out to about 64k tokens under our KV estimate. Longer chats need more memory for the cache. Figures assume an FP16 KV cache.

From the model’s config. Try other sizes in the VRAM calculator or see the context length guide.

What to do instead

• Q8_0 needs 26.6 GB and does not fit here. The GeForce RTX 5090 has 32.0 GB usable, enough for Q8.
• See the best GPU for this model family and the gpt-oss-20b model page.

Other hardware for gpt-oss-20b

• gpt-oss-20b on an RTX 3060 12GBWon’t fit
• gpt-oss-20b on an RTX 3070 TiWon’t fit
• gpt-oss-20b on an RTX 3080Won’t fit
• gpt-oss-20b on an RTX 3090Fits
• gpt-oss-20b on an RTX 4060 Ti 16GBTight
• gpt-oss-20b on an RTX 4070 Ti SuperTight

Other models on a Mac mini 24GB

• Qwen3-32B on a Mac mini 24GBWon’t fit
• Qwen3-30B-A3B on a Mac mini 24GBWon’t fit
• Qwen3.8-27B on a Mac mini 24GBWon’t fit
• Gemma 3 27B on a Mac mini 24GBWon’t fit
• Gemma 4 31B on a Mac mini 24GBWon’t fit
• Mistral Small 24B on a Mac mini 24GBTight