Gemma 2 9B at FP16 needs 18.0 GB for its weights and 40.5 GB in total at 8K context with 8 concurrent users. That means it fits on a single Mac M2 Ultra (192GB unified). Every figure is computed by tokcalc's open-source capacity model.
| GPUs | Total VRAM | VRAM needed | Decode tok/s | Aggregate tok/s | TTFT | Cost / 1M tok | Fits? |
|---|---|---|---|---|---|---|---|
| 1× Mac | 192 GB | 40.5 GB | 28.89 | 346.7 | 10.99 s | — | ✓ |
| 2× Mac | 384 GB | 40.5 GB | 49.11 | 1179 | 5.51 s | — | ✓ |
| 4× Mac | 768 GB | 40.5 GB | 98.22 | 4715 | 2.77 s | — | ✓ |
| 8× Mac | 1536 GB | 40.5 GB | 196.4 | 18859 | 1.40 s | — | ✓ |
| Context | Concurrent users | KV per request | Fits? |
|---|---|---|---|
| 4K | 123 | 1.41 GB | ✓ fits |
| 8K | 61 | 2.82 GB | ✓ fits |
| 33K | 15 | 11.27 GB | ✓ fits |
| 66K | 7 | 22.55 GB | ✓ fits |
| 131K | 3 | 45.10 GB | ✓ fits |
| GPU | GPUs | Aggregate tok/s | Cost / 1M tok |
|---|---|---|---|
| RTX 5090 32GB | 2× | 2640 | $0.1052 |
| AMD MI300X 192GB | 1× | 2297 | $0.3024 |
| AMD MI325X 288GB | 1× | 2600 | $0.3739 |
| A100 80GB SXM4 | 1× | 866.7 | $0.3846 |
| Intel Gaudi 3 128GB | 1× | 1430 | $0.3885 |
| H100 SXM5 80GB | 1× | 1452 | $0.4784 |
Yes. Gemma 2 9B at FP16 needs 40.5 GB including the KV cache, and Mac M2 Ultra (192GB unified) has 192 GB — so it fits on a single GPU.
28.89 tokens/sec per stream and 346.7 tok/s aggregate with continuous batching at 8 concurrent users. Time to first token is 10.99 s, and inter-token latency is 34.6 ms.
— per 1M output tokens at 1× Mac M2 Ultra (192GB unified). That is the marginal hardware cost — add idle capacity, ops, and egress for the real figure.
18.0 GB for the weights at FP16, plus 22.5 GB of KV cache for 8 concurrent requests at 8K context — 40.5 GB total. Every extra concurrent user at long context costs more, so leave headroom.
It works. Compare — per 1M tokens against the alternatives below — the cheapest option that fits the same workload is 8× RTX 3080 10GB at $0.0248, and the fastest is 8× RTX 3080 10GB at 17916 tok/s.
Same formulas, your context length, concurrency, and quantisation.