Phi-3 Mini 3.8B at FP16 needs 7.6 GB for its weights and 33.4 GB in total at 8K context with 8 concurrent users. That means it fits on a single RTX 6000 Ada 48GB. 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× RTX | 48 GB | 33.4 GB | 82.11 | 985.3 | 1.40 s | $0.2255 | ✓ |
| 2× RTX | 96 GB | 33.4 GB | 139.6 | 3350 | 716.8 ms | $0.1327 | ✓ |
| 4× RTX | 192 GB | 33.4 GB | 279.2 | 13400 | 373.4 ms | $0.0663 | ✓ |
| 8× RTX | 384 GB | 33.4 GB | 558.3 | 53598 | 201.7 ms | $0.0332 | ✓ |
| Context | Concurrent users | KV per request | Fits? |
|---|---|---|---|
| 4K | 25 | 1.61 GB | ✓ fits |
| 8K | 12 | 3.22 GB | ✓ fits |
| 33K | 3 | 12.88 GB | ✓ fits |
| 66K | 1 | 25.77 GB | ✓ fits |
| 131K | 0 | 51.54 GB | ✗ does not fit |
| GPU | GPUs | Aggregate tok/s | Cost / 1M tok |
|---|---|---|---|
| RTX 5090 32GB | 2× | 6253 | $0.0444 |
| AMD MI300X 192GB | 1× | 5439 | $0.1277 |
| A100 40GB SXM4 | 1× | 1591 | $0.1572 |
| AMD MI325X 288GB | 1× | 6158 | $0.1579 |
| A100 80GB SXM4 | 1× | 2053 | $0.1624 |
| Intel Gaudi 3 128GB | 1× | 3387 | $0.1640 |
Yes. Phi-3 Mini 3.8B at FP16 needs 33.4 GB including the KV cache, and RTX 6000 Ada 48GB has 48 GB — so it fits on a single GPU.
82.11 tokens/sec per stream and 985.3 tok/s aggregate with continuous batching at 8 concurrent users. Time to first token is 1.40 s, and inter-token latency is 12.2 ms.
$0.2255 per 1M output tokens at 1× RTX 6000 Ada 48GB ($0.8000/hr). That is the marginal hardware cost — add idle capacity, ops, and egress for the real figure.
7.6 GB for the weights at FP16, plus 25.8 GB of KV cache for 8 concurrent requests at 8K context — 33.4 GB total. Every extra concurrent user at long context costs more, so leave headroom.
It works. Compare $0.2255 per 1M tokens against the alternatives below — the cheapest option that fits the same workload is 4× RTX 3080 10GB at $0.0209, and the fastest is 1× Cerebras CS-3 (WSE-3) at 20526 tok/s.
Same formulas, your context length, concurrency, and quantisation.