Speed test matrix
Phi-4-reasoning-plus-NVFP4 on RTX 3090 24GB
vllm · 0.32.0 · NVFP43 contexts (0–24K) × 8 concurrency levels (1–128) · prefill at 8K, 16K, 24K
Hardware
- Type
- Discrete GPU
- GPU
- RTX 3090
- VRAM
- 24 GB
- CPU
- Intel Core i7-9700K (8C)
- RAM
- 32 GB
- OS
- Ubuntu 24.04.5
Engine
- Engine
- vllm
- Version
- 0.32.0
- Quantization
- NVFP4
- Backend
- cuda
- Repository
- github.com/vllm-project/vllm
- Build
- vllm/vllm-openai:v0.32.0-x86_64
Run
- Served model
- bench
- Revision
- main
- Benchmark tool
- llm-inference-bench v0.8.0
- Decode test
- Fixed duration
- Prefill mode
- Measured during decode warm-up
- Time per measurement
- 30 s
- Max output
- 8,192 tokens
Launch command
# Untuned out-of-the-box baseline. Spec decode: none. KV cache: int4_per_token_head # 1x RTX 3090 24GB (Zagitta/gpu-unlock), 420 W limit, PCIe Gen3 x16 | Intel Core i7-9700K 8C | 32 GB DDR4 | Ubuntu 24.04.5, NVIDIA driver 580.178.04 vllm serve nvidia/Phi-4-reasoning-plus-NVFP4 --max-model-len 32768 --gpu-memory-utilization 0.94 --max-num-seqs 128 --enable-prefix-caching --trust-remote-code --kv-cache-dtype int4_per_token_head --attention-backend TRITON_ATTN
Prefill
prompt tok/s by context length8K context2,3653,569 ms TTFT
16K context1,7169,623 ms TTFT
24K context1,35118,207 ms TTFT
Sustained decode
total tok/s · rows are context length, columns are simultaneous requests| Context | 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 |
|---|---|---|---|---|---|---|---|---|
| 0 | 72.643 ms TTFT | 140.868 ms TTFT | 262.272 ms TTFT | 468.177 ms TTFT | 814.690 ms TTFT | Over capacity | Over capacity | Over capacity |
| 16K | 51.4102 ms TTFT | 91.9150 ms TTFT | 135.8216 ms TTFT | 178.4299 ms TTFT | Over capacity | Over capacity | Over capacity | Over capacity |
| 24K | 44.7144 ms TTFT | 78.2202 ms TTFT | 108.8290 ms TTFT | Over capacity | Over capacity | Over capacity | Over capacity | Over capacity |
Over capacity: not run because this many requests at this context would exceed the server's KV cache.
TTFT is measured after the benchmark warms the server's prompt cache, so it mostly excludes prefill.
All measurements
Latencies are medians. Total tok/s is output across all simultaneous requests.| Phase | Context | Requests at once | Status | Total tok/s | Per request tok/s | TTFT | Time between tokens | Average active requests | Completed requests | Output tokens | Measured for |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Prefill | 8K | 1 | Valid | 2,365.0 | — | 3,569 ms | — | — | 1 | — | — |
| Prefill | 16K | 1 | Valid | 1,716.0 | — | 9,623 ms | — | — | 1 | — | — |
| Prefill | 24K | 1 | Valid | 1,351.0 | — | 18,207 ms | — | — | 1 | — | — |
| Sustained decode | 0 | 1 | Valid | 72.6 | 73.0 | 43 ms | 13.7 ms | 1.0 | 0 | 2,176 | 30.0 s |
| Sustained decode | 0 | 2 | Valid | 140.8 | 71.0 | 68 ms | 14.1 ms | 2.0 | 0 | 4,224 | 30.0 s |
| Sustained decode | 0 | 4 | Valid | 262.2 | 66.4 | 72 ms | 15.1 ms | 4.0 | 0 | 7,864 | 30.0 s |
| Sustained decode | 0 | 8 | Valid | 468.1 | 59.9 | 77 ms | 16.7 ms | 8.0 | 0 | 14,040 | 30.0 s |
| Sustained decode | 0 | 16 | Valid | 814.6 | 52.8 | 90 ms | 18.9 ms | 16.0 | 0 | 24,432 | 30.0 s |
| Sustained decode | 0 | 32 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 0 | 64 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 0 | 128 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 16K | 1 | Valid | 51.4 | 51.5 | 102 ms | 19.4 ms | 1.0 | 0 | 1,540 | 30.0 s |
| Sustained decode | 16K | 2 | Valid | 91.9 | 46.1 | 150 ms | 21.7 ms | 2.0 | 0 | 2,758 | 30.0 s |
| Sustained decode | 16K | 4 | Valid | 135.8 | 34.1 | 216 ms | 29.4 ms | 4.0 | 0 | 4,075 | 30.0 s |
| Sustained decode | 16K | 8 | Valid | 178.4 | 22.3 | 299 ms | 44.8 ms | 8.0 | 0 | 5,352 | 30.0 s |
| Sustained decode | 16K | 16 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 16K | 32 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 16K | 64 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 16K | 128 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 24K | 1 | Valid | 44.7 | 44.8 | 144 ms | 22.3 ms | 1.0 | 0 | 1,340 | 30.0 s |
| Sustained decode | 24K | 2 | Valid | 78.2 | 39.1 | 202 ms | 25.5 ms | 2.0 | 0 | 2,344 | 30.0 s |
| Sustained decode | 24K | 4 | Valid | 108.8 | 27.3 | 290 ms | 36.7 ms | 4.0 | 0 | 3,264 | 30.0 s |
| Sustained decode | 24K | 8 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 24K | 16 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 24K | 32 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 24K | 64 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 24K | 128 | Over capacity | — | — | — | — | — | — | — | — |
Over capacity: not run because this many requests at this context would exceed the server's KV cache.