Speed test matrix
granite-4.2-3b-fp8 on RTX 3090 24GB
vllm · 0.32.0 · FP85 contexts (0–120K) × 8 concurrency levels (1–128) · prefill at 8K, 16K, 32K, 64K, 120K
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
- 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 ibm-granite/granite-4.2-3b-fp8 --max-model-len 131072 --gpu-memory-utilization 0.94 --max-num-seqs 128 --enable-prefix-caching --trust-remote-code
Prefill
prompt tok/s by context length8K context12.3K668 ms TTFT
16K context9,9951,633 ms TTFT
32K context7,4464,361 ms TTFT
64K context4,89913,222 ms TTFT
120K context3,04139,885 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 | 159.916 ms TTFT | 298.818 ms TTFT | 554.122 ms TTFT | 960.229 ms TTFT | 1,601.645 ms TTFT | Over capacity | Over capacity | Over capacity |
| 16K | 127.955 ms TTFT | 214.576 ms TTFT | 370.1116 ms TTFT | 489.4200 ms TTFT | Over capacity | Over capacity | Over capacity | Over capacity |
| 32K | 107.9103 ms TTFT | 166.0135 ms TTFT | 272.1203 ms TTFT | Over capacity | Over capacity | Over capacity | Over capacity | Over capacity |
| 64K | 81.8193 ms TTFT | 114.0253 ms TTFT | Over capacity | Over capacity | Over capacity | Over capacity | Over capacity | Over capacity |
| 120K | 57.2386 ms TTFT | Over capacity | Over capacity | 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 | 12.3K | — | 668 ms | — | — | 1 | — | — |
| Prefill | 16K | 1 | Valid | 9,995.0 | — | 1,633 ms | — | — | 1 | — | — |
| Prefill | 32K | 1 | Valid | 7,446.0 | — | 4,361 ms | — | — | 1 | — | — |
| Prefill | 64K | 1 | Valid | 4,899.0 | — | 13,222 ms | — | — | 1 | — | — |
| Prefill | 120K | 1 | Valid | 3,041.0 | — | 39,885 ms | — | — | 1 | — | — |
| Sustained decode | 0 | 1 | Valid | 159.9 | 161.3 | 16 ms | 6.2 ms | 1.0 | 0 | 4,798 | 30.0 s |
| Sustained decode | 0 | 2 | Valid | 298.8 | 151.9 | 18 ms | 6.6 ms | 2.0 | 0 | 8,962 | 30.0 s |
| Sustained decode | 0 | 4 | Valid | 554.1 | 141.9 | 22 ms | 7.0 ms | 4.0 | 0 | 16,623 | 30.0 s |
| Sustained decode | 0 | 8 | Valid | 960.2 | 124.8 | 29 ms | 8.0 ms | 8.0 | 0 | 28,800 | 30.0 s |
| Sustained decode | 0 | 16 | Valid | 1,601.6 | 106.2 | 45 ms | 9.4 ms | 16.0 | 0 | 48,048 | 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 | 127.9 | 128.3 | 55 ms | 7.8 ms | 1.0 | 0 | 3,837 | 30.0 s |
| Sustained decode | 16K | 2 | Valid | 214.5 | 107.8 | 76 ms | 9.3 ms | 2.0 | 0 | 6,434 | 30.0 s |
| Sustained decode | 16K | 4 | Valid | 370.1 | 93.2 | 116 ms | 10.7 ms | 4.0 | 0 | 11,100 | 30.0 s |
| Sustained decode | 16K | 8 | Valid | 489.4 | 62.2 | 200 ms | 16.1 ms | 8.0 | 0 | 14,680 | 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 | 32K | 1 | Valid | 107.9 | 108.1 | 103 ms | 9.3 ms | 1.0 | 0 | 3,236 | 30.0 s |
| Sustained decode | 32K | 2 | Valid | 166.0 | 83.2 | 135 ms | 12.0 ms | 2.0 | 0 | 4,978 | 30.0 s |
| Sustained decode | 32K | 4 | Valid | 272.1 | 68.0 | 203 ms | 14.7 ms | 4.0 | 0 | 8,160 | 30.0 s |
| 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 | Valid | 81.8 | 82.0 | 193 ms | 12.2 ms | 1.0 | 0 | 2,453 | 30.0 s |
| Sustained decode | 64K | 2 | Valid | 114.0 | 57.1 | 253 ms | 17.5 ms | 2.0 | 0 | 3,418 | 30.0 s |
| Sustained decode | 64K | 4 | Over capacity | — | — | — | — | — | — | — | — |
| 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 | 120K | 1 | Valid | 57.2 | 57.4 | 386 ms | 17.4 ms | 1.0 | 0 | 1,717 | 30.0 s |
| Sustained decode | 120K | 2 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 120K | 4 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 120K | 8 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 120K | 16 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 120K | 32 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 120K | 64 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 120K | 128 | Over capacity | — | — | — | — | — | — | — | — |
Over capacity: not run because this many requests at this context would exceed the server's KV cache.