# Can I run gpt-oss 120B on Apple M5 Max (128GB)?

Updated: 2026-06-15

**Yes, it runs.** Runs at Q4_K_M using ~62.4 GB of ~96 GB usable.

- Model: 117B (MoE, 5.1B active), Q4_K_M 59.03 GB
- Device: 128 GB unified, ~96 GB usable for weights
- Needs ~62.4 GB at Q4_K_M; recommended quant: Q4_K_M
- Best tool on macOS: LM Studio
- Command: `ollama run gpt-oss:120b`

Estimate. Method: weights + KV cache + ~0.8GB overhead. Sources: https://ollama.com/library/gpt-oss, https://ollama.com/library/gpt-oss/tags, https://huggingface.co/ggml-org/gpt-oss-120b-GGUF, https://huggingface.co/openai/gpt-oss-120b.

More: https://localmodel.run/can-i-run/gpt-oss-120b/apple-m5-max-128gb