Can I Run DeepSeek V3 on Apple M3 Ultra?
Written by Jakub Rusinowski · Last updated July 12, 2026
Only with offload — DeepSeek V3 (685B MoE) at Q4_K_M needs 419.5 GB at 8K context (413.6 GB weights + 5.9 GB KV cache/overhead) against the Apple M3 Ultra's 384 GB usable memory, so part of it spills onto CPU/system RAM and speed drops sharply.
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Apple M3 Ultra Specs
| VRAM | 512 GB unified memory |
| Memory Bandwidth | 819 GB/s |
DeepSeek V3 (685B MoE) on the Apple M3 Ultra: VRAM by quantization
| Quant | VRAM needed | Fits 512 GB? | Max context | Whole PC |
|---|---|---|---|---|
| F16 | 1375.9 GB | ✗ No | — | — |
| Q8_0 | 733.7 GB | ✗ No | — | — |
| Q6_K | 567.6 GB | ✗ No | — | — |
| Q5_K_M | 491.4 GB | ✗ No | — | — |
| Q4_K_M | 419.5 GB | ✗ No | — | — |
| Q3_K_M | 297.9 GB | ✓ Yes | 64K | — |
| Q2_K | 231.1 GB | ✓ Yes | 64K | — |
Assumes an 8K-token context with an f16 KV cache, on an estimated architecture — this model publishes no config we can read. A longer window needs more; a quantized KV cache needs less. “Max context” is the largest window that still fits in 512 GB of unified memory. Figures are estimates from parameter count, quantization and memory bandwidth — the analyzer lets you tune KV-cache quant and context.
Context costs VRAM too. At Q4_K_M on the Apple M3 Ultra: 8K 419.5 GB ✗ · 32K 434.8 GB ✗ · 125K 494.1 GB ✗. Past 8K it no longer fits 512 GB — a q8_0 KV cache buys roughly half of that back, which the calculator will price for you.
Why It Does Not Fit
Every DeepSeek V3 variant requires more VRAM than the Apple M3 Ultra provides (512 GB).
DeepSeek V3 needs ~420 GB but this GPU has 512 GB. Rent a 8× H100 (640 GB)-class GPU by the hour instead of buying one:
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FAQ
Is the Apple M3 Ultra enough to run DeepSeek V3 locally?
Only with offload — DeepSeek V3 (685B MoE) at Q4_K_M needs 419.5 GB at 8K context (413.6 GB weights + 5.9 GB KV cache/overhead) against the Apple M3 Ultra's 384 GB usable memory, so part of it spills onto CPU/system RAM and speed drops sharply.
DeepSeek V3 on Other GPUs
VRAM Tier
Troubleshooting
- Ollama: "model requires more system memory than is available"
- Out of memory at long context (the KV cache, not the weights)
Buying Guide
← Can I Run It? | DeepSeek V3 Model Page | Apple M3 Ultra GPU Page | VRAM calculator | Check Your Hardware