Compatibility Check
Can I Run Llama 3.1 405B on Apple M3 Ultra?
Yes — Apple M3 Ultra runs Llama 3.1 405B fully on GPU at the Q2_K quantization.
Estimated ~3.4 tokens/sec on the Q2_K quantization.
Full GPU
Best variant: Q2_K
Full GPU inference — 192 GB VRAM meets the 160 GB recommendation.
- GPU VRAM
- 192 GB
- Min VRAM (best fit)
- 150 GB
- Recommended VRAM
- 160 GB
- Estimated tok/s
- ~3.4
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Every Llama 3.1 405B quantization on Apple M3 Ultra
Each row runs the compatibility engine against your VRAM, RAM, and the model's requirements.
| Quantization | File Size | Min VRAM | Rec VRAM | Context | Verdict | Estimated tok/s |
|---|---|---|---|---|---|---|
| Q2_KBest fit | 145 GB | 150 GB | 160 GB | 4K / 128K | Full GPU | ~3.4 |
| Q4_K_M | 230 GB | 235 GB | 256 GB | 4K / 128K | Can't Run | — |
Apple M3 Ultra is solid pick for Llama 3.1 405B
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