Phi-4 14B at FP16 needs 28.0 GB for its weights and 38.7 GB in total at 8K context with 8 concurrent users. That means it fits on a single A100 80GB SXM4. 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× A100 | 80 GB | 38.7 GB | 46.43 | 557.1 | 1.52 s | $0.5983 | ✓ |
| 2× A100 | 160 GB | 38.7 GB | 78.93 | 1894 | 777.8 ms | $0.3519 | ✓ |
| 4× A100 | 320 GB | 38.7 GB | 157.9 | 7577 | 403.9 ms | $0.1760 | ✓ |
| 8× A100 | 640 GB | 38.7 GB | 315.7 | 30309 | 217.0 ms | $0.0880 | ✓ |
| Context | Concurrent users | KV per request | Fits? |
|---|---|---|---|
| 4K | 77 | 687.2 MB | ✓ fits |
| 8K | 38 | 1.34 GB | ✓ fits |
| 33K | 9 | 5.37 GB | ✓ fits |
| 66K | 4 | 10.74 GB | ✓ fits |
| 131K | 2 | 21.47 GB | ✓ fits |
| GPU | GPUs | Aggregate tok/s | Cost / 1M tok |
|---|---|---|---|
| RTX 5090 32GB | 2× | 1697 | $0.1637 |
| AMD MI300X 192GB | 1× | 1476 | $0.4704 |
| A100 40GB SXM4 | 1× | 431.8 | $0.5790 |
| AMD MI325X 288GB | 1× | 1671 | $0.5817 |
| Intel Gaudi 3 128GB | 1× | 919.3 | $0.6043 |
| H100 SXM5 80GB | 1× | 933.2 | $0.7441 |
Yes. Phi-4 14B at FP16 needs 38.7 GB including the KV cache, and A100 80GB SXM4 has 80 GB — so it fits on a single GPU.
46.43 tokens/sec per stream and 557.1 tok/s aggregate with continuous batching at 8 concurrent users. Time to first token is 1.52 s, and inter-token latency is 21.5 ms.
$0.5983 per 1M output tokens at 1× A100 80GB SXM4 ($1.20/hr). That is the marginal hardware cost — add idle capacity, ops, and egress for the real figure.
28.0 GB for the weights at FP16, plus 10.7 GB of KV cache for 8 concurrent requests at 8K context — 38.7 GB total. Every extra concurrent user at long context costs more, so leave headroom.
It works. Compare $0.5983 per 1M tokens against the alternatives below — the cheapest option that fits the same workload is 4× RTX 3080 10GB at $0.0772, and the fastest is 1× Cerebras CS-3 (WSE-3) at 5571 tok/s.
Same formulas, your context length, concurrency, and quantisation.