OLMo 2 13B at FP16 needs 26.0 GB for its weights and 36.7 GB in total at 8K context with 8 concurrent users. That means it needs 2× RTX 5090 32GB. Every figure is computed by tokcalc's open-source capacity model.
RTX 5090 32GB has no NVLink, so 2-way tensor parallelism runs over PCIe. tokcalc applies a flat 0.85× multi-GPU efficiency factor for this, which is realistic for NVLink-equipped datacenter cards but optimistic for PCIe scale-out — treat the throughput and cost figures for this configuration as an upper bound, and measure before committing.
| GPUs | Total VRAM | VRAM needed | Decode tok/s | Aggregate tok/s | TTFT | Cost / 1M tok | Fits? |
|---|---|---|---|---|---|---|---|
| 1× RTX | 32 GB | 36.7 GB | 0.000 | 0.000 | — | — | ✗ |
| 2× RTX | 64 GB | 36.7 GB | 76.16 | 1828 | 2.07 s | $0.1520 | ✓ |
| 4× RTX | 128 GB | 36.7 GB | 152.3 | 7311 | 1.05 s | $0.0760 | ✓ |
| 8× RTX | 256 GB | 36.7 GB | 304.6 | 29245 | 540.4 ms | $0.0380 | ✓ |
| Context | Concurrent users | KV per request | Fits? |
|---|---|---|---|
| 4K | 56 | 687.2 MB | ✓ fits |
| 8K | 28 | 1.34 GB | ✓ fits |
| 33K | 7 | 5.37 GB | ✓ fits |
| 66K | 3 | 10.74 GB | ✓ fits |
| 131K | 1 | 21.47 GB | ✓ fits |
| GPU | GPUs | Aggregate tok/s | Cost / 1M tok |
|---|---|---|---|
| AMD MI300X 192GB | 1× | 1590 | $0.4368 |
| A100 40GB SXM4 | 1× | 465.0 | $0.5376 |
| AMD MI325X 288GB | 1× | 1800 | $0.5401 |
| A100 80GB SXM4 | 1× | 600.0 | $0.5556 |
| Intel Gaudi 3 128GB | 1× | 990.0 | $0.5612 |
| H100 SXM5 80GB | 1× | 1005 | $0.6910 |
Yes, but it needs 2× RTX 5090 32GB. At FP16 the total footprint is 36.7 GB (26.0 GB of weights plus 10.7 GB of KV cache at 8K × 8 concurrent users), against 64 GB of available VRAM across 2 GPUs.
76.16 tokens/sec per stream and 1828 tok/s aggregate with continuous batching at 8 concurrent users. Time to first token is 2.07 s, and inter-token latency is 13.1 ms.
$0.1520 per 1M output tokens at 2× RTX 5090 32GB ($0.5000/hr). That is the marginal hardware cost — add idle capacity, ops, and egress for the real figure.
26.0 GB for the weights at FP16, plus 10.7 GB of KV cache for 8 concurrent requests at 8K context — 36.7 GB total. Every extra concurrent user at long context costs more, so leave headroom.
It works. Compare $0.1520 per 1M tokens against the alternatives below — the cheapest option that fits the same workload is 4× RTX 3080 10GB at $0.0717, and the fastest is 1× Cerebras CS-3 (WSE-3) at 6000 tok/s.
Same formulas, your context length, concurrency, and quantisation.