Speed test matrix
gemma-4-12B-it-FP8-Dynamic on RTX 3090 24GB
vllm · 0.32.0 · FP8 dynamic6 contexts (0–248K) × 8 concurrency levels (1–128) · prefill at 8K, 16K, 32K, 64K, 128K
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
- FP8 dynamic
- 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 # 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 RedHatAI/gemma-4-12B-it-FP8-Dynamic --max-model-len 262144 --gpu-memory-utilization 0.94 --max-num-seqs 128 --enable-prefix-caching --trust-remote-code --language-model-only
Prefill
prompt tok/s by context length8K context3,8472,083 ms TTFT
16K context3,2194,932 ms TTFT
32K context2,54512,417 ms TTFT
64K context1,79735,087 ms TTFT
128K context1,125111,928 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 | 57.134 ms TTFT | 111.239 ms TTFT | 210.950 ms TTFT | 384.360 ms TTFT | 657.499 ms TTFT | 935.4Requests queued161 ms TTFT | Over capacity | Over capacity |
| 16K | 50.595 ms TTFT | 99.9125 ms TTFT | 192.5170 ms TTFT | Looped | Over capacity | Over capacity | Over capacity | Over capacity |
| 32K | 47.1162 ms TTFT | Looped | Looped | Over capacity | Over capacity | Over capacity | Over capacity | Over capacity |
| 64K | Looped | Looped | Looped | Over capacity | Over capacity | Over capacity | Over capacity | Over capacity |
| 128K | 37.4651 ms TTFT | 74.3896 ms TTFT | Over capacity | Over capacity | Over capacity | Over capacity | Over capacity | Over capacity |
| 248K | 29.1Requests queued1,392 ms TTFT | Over capacity | Over capacity | Over capacity | Over capacity | Over capacity | Over capacity | Over capacity |
Requests queued: the server could not run all requests at once, so some waited in a queue. Looped: the model kept repeating the same text, so the benchmark discarded this measurement. 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 | 3,847.0 | — | 2,083 ms | — | — | 1 | — | — |
| Prefill | 16K | 1 | Valid | 3,219.0 | — | 4,932 ms | — | — | 1 | — | — |
| Prefill | 32K | 1 | Valid | 2,545.0 | — | 12,417 ms | — | — | 1 | — | — |
| Prefill | 64K | 1 | Valid | 1,797.0 | — | 35,087 ms | — | — | 1 | — | — |
| Prefill | 128K | 1 | Valid | 1,125.0 | — | 111,928 ms | — | — | 1 | — | — |
| Sustained decode | 0 | 1 | Valid | 57.1 | 57.4 | 34 ms | 17.4 ms | 1.0 | 0 | 1,713 | 30.0 s |
| Sustained decode | 0 | 2 | Valid | 111.2 | 56.0 | 39 ms | 17.9 ms | 2.0 | 0 | 3,336 | 30.0 s |
| Sustained decode | 0 | 4 | Valid | 210.9 | 53.3 | 50 ms | 18.8 ms | 4.0 | 0 | 6,327 | 30.0 s |
| Sustained decode | 0 | 8 | Valid | 384.3 | 49.0 | 60 ms | 20.4 ms | 8.0 | 0 | 11,528 | 30.0 s |
| Sustained decode | 0 | 16 | Valid | 657.4 | 42.5 | 99 ms | 23.5 ms | 16.0 | 0 | 19,712 | 30.0 s |
| Sustained decode | 0 | 32 | Requests queued | 935.4 | 37.1 | 161 ms | 26.9 ms | 26.2 | 0 | 28,062 | 30.0 s |
| Sustained decode | 0 | 64 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 0 | 128 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 16K | 1 | Valid | 50.5 | 50.6 | 95 ms | 19.8 ms | 1.0 | 0 | 1,513 | 30.0 s |
| Sustained decode | 16K | 2 | Valid | 99.9 | 50.1 | 125 ms | 20.0 ms | 2.0 | 0 | 2,996 | 30.0 s |
| Sustained decode | 16K | 4 | Valid | 192.5 | 48.3 | 170 ms | 20.7 ms | 4.0 | 0 | 5,772 | 30.0 s |
| Sustained decode | 16K | 8 | Looped | — | — | — | — | — | 0 | 0 | — |
| 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 | 32K | 1 | Valid | 47.1 | 47.2 | 162 ms | 21.2 ms | 1.0 | 0 | 1,413 | 30.0 s |
| Sustained decode | 32K | 2 | Looped | — | — | — | — | — | 0 | 0 | — |
| Sustained decode | 32K | 4 | Looped | — | — | — | — | — | 0 | 0 | — |
| Sustained decode | 32K | 8 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 32K | 16 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 32K | 32 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 32K | 64 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 32K | 128 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 64K | 1 | Looped | — | — | — | — | — | 0 | 0 | — |
| Sustained decode | 64K | 2 | Looped | — | — | — | — | — | 0 | 0 | — |
| Sustained decode | 64K | 4 | Looped | — | — | — | — | — | 0 | 0 | — |
| Sustained decode | 64K | 8 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 64K | 16 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 64K | 32 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 64K | 64 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 64K | 128 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 128K | 1 | Valid | 37.4 | 37.5 | 651 ms | 26.6 ms | 1.0 | 0 | 1,122 | 30.0 s |
| Sustained decode | 128K | 2 | Valid | 74.3 | 37.2 | 896 ms | 26.9 ms | 2.0 | 0 | 2,229 | 30.0 s |
| Sustained decode | 128K | 4 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 128K | 8 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 128K | 16 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 128K | 32 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 128K | 64 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 128K | 128 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 248K | 1 | Requests queued | 29.1 | 30.0 | 1,392 ms | 33.3 ms | 1.0 | 0 | 873 | 30.0 s |
| Sustained decode | 248K | 2 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 248K | 4 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 248K | 8 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 248K | 16 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 248K | 32 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 248K | 64 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 248K | 128 | Over capacity | — | — | — | — | — | — | — | — |
Requests queued: the server could not run all requests at once, so some waited in a queue. Looped: the model kept repeating the same text, so the benchmark discarded this measurement. Over capacity: not run because this many requests at this context would exceed the server's KV cache.