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
- AMD Ryzen 9 7900X (12C)
- 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), 350 W limit (VBIOS max), PCIe Gen4 x16 | AMD Ryzen 9 7900X 12C | 32 GB DDR5 | Ubuntu 24.04.5, NVIDIA driver 595.99.02 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 context2,0354,147 ms TTFT
16K context1,48511,119 ms TTFT
24K context1,19120,644 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 | 70.346 ms TTFT | 136.238 ms TTFT | 252.841 ms TTFT | 449.646 ms TTFT | 779.674 ms TTFT | Over capacity | Over capacity | Over capacity |
| 16K | 49.190 ms TTFT | 86.9141 ms TTFT | 126.8213 ms TTFT | 164.5263 ms TTFT | Over capacity | Over capacity | Over capacity | Over capacity |
| 24K | 42.8125 ms TTFT | 73.6180 ms TTFT | 101.0278 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 | 2,035.0 | — | 4,147 ms | — | — | 1 | — | — |
| Prefill | 16K | 1 | Valid | 1,485.0 | — | 11,119 ms | — | — | 1 | — | — |
| Prefill | 24K | 1 | Valid | 1,191.0 | — | 20,644 ms | — | — | 1 | — | — |
| Sustained decode | 0 | 1 | Valid | 70.3 | 70.7 | 46 ms | 14.1 ms | 1.0 | 0 | 2,109 | 30.0 s |
| Sustained decode | 0 | 2 | Valid | 136.2 | 68.7 | 38 ms | 14.6 ms | 2.0 | 0 | 4,086 | 30.0 s |
| Sustained decode | 0 | 4 | Valid | 252.8 | 64.1 | 41 ms | 15.6 ms | 4.0 | 0 | 7,585 | 30.0 s |
| Sustained decode | 0 | 8 | Valid | 449.6 | 57.5 | 46 ms | 17.4 ms | 8.0 | 0 | 13,489 | 30.0 s |
| Sustained decode | 0 | 16 | Valid | 779.6 | 50.6 | 74 ms | 19.8 ms | 16.0 | 0 | 23,376 | 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 | 49.1 | 49.2 | 90 ms | 20.3 ms | 1.0 | 0 | 1,473 | 30.0 s |
| Sustained decode | 16K | 2 | Valid | 86.9 | 43.6 | 141 ms | 23.0 ms | 2.0 | 0 | 2,606 | 30.0 s |
| Sustained decode | 16K | 4 | Valid | 126.8 | 31.8 | 213 ms | 31.5 ms | 4.0 | 0 | 3,804 | 30.0 s |
| Sustained decode | 16K | 8 | Valid | 164.5 | 20.6 | 263 ms | 48.5 ms | 8.0 | 0 | 4,928 | 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 | 42.8 | 42.8 | 125 ms | 23.3 ms | 1.0 | 0 | 1,283 | 30.0 s |
| Sustained decode | 24K | 2 | Valid | 73.6 | 36.9 | 180 ms | 27.1 ms | 2.0 | 0 | 2,207 | 30.0 s |
| Sustained decode | 24K | 4 | Valid | 101.0 | 25.3 | 278 ms | 39.6 ms | 4.0 | 0 | 3,028 | 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.