Can the Apple M4 Pro (48GB) run gpt-oss 20B?
- FP16
- Q8_0
- Q6_K
- Q5_K_M
- Q4_K_M
- Q3_K_M
- Q2_K
Yes. The Apple M4 Pro (48GB) can run gpt-oss 20B fully in unified memory at Q8_0 (near-lossless), using about 23.2 GB of the 36 GB available, at roughly 43 tokens/second.
Run it with Ollama
With Ollama installed, one command downloads and starts gpt-oss 20B:
ollama run gpt-oss:20bOllama's default download is Q4_K_M (about 13.7 GB here). You have room for Q8_0, which is near-lossless: pick that GGUF in LM Studio or from Hugging Face.
New to this? Step-by-step setup for the Apple M4 Pro (48GB)
Run it in the cloud
No Apple M4 Pro (48GB)? Run gpt-oss 20B in the cloud.
Rent a cloud GPU by the hour. No upfront cost, stop any time.
Memory needed by quantization
At 8,192 tokens of context. The black line marks the 36 GB the Apple M4 Pro (48GB) can use. macOS lets the GPU use about 36 GB of the 48 GB unified memory by default.
| Quant | Quality | Memory | Fits? | Speed | |
|---|---|---|---|---|---|
| FP16 | Full quality | 42.8 GB | Too big | — | |
| Q8_0 | Near-lossless | 23.2 GB | Fits | ~43 tok/s | |
| Q6_K | Excellent | 18.1 GB | Fits | ~55 tok/s | |
| Q5_K_M | Very good | 15.9 GB | Fits | ~64 tok/s | |
| Q4_K_M | Good, most popular | 13.7 GB | Fits | ~75 tok/s | |
| Q3_K_M | Noticeably degraded | 11.2 GB | Fits | ~93 tok/s | |
| Q2_K | Heavily degraded | 8.8 GB | Fits | ~121 tok/s |
GPUs that run gpt-oss 20B comfortably
Models that run well on the Apple M4 Pro (48GB)
Frequently asked questions
Can Apple M4 Pro (48GB) run gpt-oss 20B?
Yes. The Apple M4 Pro (48GB) can run gpt-oss 20B fully in unified memory at Q8_0 (near-lossless), using about 23.2 GB of the 36 GB available, at roughly 43 tokens/second.
How much VRAM does gpt-oss 20B need?
About 13.7 GB at Q4_K_M with 8,192 tokens of context, and about 42.8 GB at full FP16 precision.
How fast is gpt-oss 20B on the Apple M4 Pro (48GB)?
Roughly 43 tokens per second at Q8_0, estimated from the Apple M4 Pro (48GB)'s 273 GB/s memory bandwidth.