Speed test matrix
Qwen3.5-4B-AWQ-4bit on RTX 3090 24GB
vllm · 0.32.0 · AWQ 4-bit6 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
- AMD Ryzen 9 7900X (12C)
- RAM
- 32 GB
- OS
- Ubuntu 24.04.5
Engine
- Engine
- vllm
- Version
- 0.32.0
- Quantization
- AWQ 4-bit
- 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), 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 cyankiwi/Qwen3.5-4B-AWQ-4bit --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 context10.6K773 ms TTFT
16K context9,9191,635 ms TTFT
32K context8,7833,676 ms TTFT
64K context7,1239,044 ms TTFT
128K context5,29724,295 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 | 181.724 ms TTFT | 331.338 ms TTFT | 618.950 ms TTFT | 1,081.089 ms TTFT | 1,787.8151 ms TTFT | 2,596.1170 ms TTFT | 3,263.4467 ms TTFT | Over capacity |
| 16K | 163.479 ms TTFT | 281.4109 ms TTFT | 508.0175 ms TTFT | 812.0297 ms TTFT | 1,132.7585 ms TTFT | Over capacity | Over capacity | Over capacity |
| 32K | 149.177 ms TTFT | 243.695 ms TTFT | 422.3146 ms TTFT | 625.4234 ms TTFT | Over capacity | Over capacity | Over capacity | Over capacity |
| 64K | 126.8133 ms TTFT | 192.2168 ms TTFT | 312.9254 ms TTFT | Over capacity | Over capacity | Over capacity | Over capacity | Over capacity |
| 128K | 97.5355 ms TTFT | 135.0434 ms TTFT | Over capacity | Over capacity | Over capacity | Over capacity | Over capacity | Over capacity |
| 248K | 67.9706 ms TTFT | 86.7864 ms TTFT | 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 | 10.6K | — | 773 ms | — | — | 1 | — | — |
| Prefill | 16K | 1 | Valid | 9,919.0 | — | 1,635 ms | — | — | 1 | — | — |
| Prefill | 32K | 1 | Valid | 8,783.0 | — | 3,676 ms | — | — | 1 | — | — |
| Prefill | 64K | 1 | Valid | 7,123.0 | — | 9,044 ms | — | — | 1 | — | — |
| Prefill | 128K | 1 | Valid | 5,297.0 | — | 24,295 ms | — | — | 1 | — | — |
| Sustained decode | 0 | 1 | Valid | 181.7 | 182.7 | 24 ms | 5.5 ms | 1.0 | 0 | 5,451 | 30.0 s |
| Sustained decode | 0 | 2 | Valid | 331.3 | 166.9 | 38 ms | 6.0 ms | 2.0 | 0 | 9,938 | 30.0 s |
| Sustained decode | 0 | 4 | Valid | 618.9 | 156.5 | 50 ms | 6.4 ms | 4.0 | 0 | 18,568 | 30.0 s |
| Sustained decode | 0 | 8 | Valid | 1,081.0 | 137.5 | 89 ms | 7.3 ms | 8.0 | 0 | 32,424 | 30.0 s |
| Sustained decode | 0 | 16 | Valid | 1,787.8 | 114.5 | 151 ms | 8.7 ms | 16.0 | 0 | 53,633 | 30.0 s |
| Sustained decode | 0 | 32 | Valid | 2,596.1 | 83.0 | 170 ms | 12.0 ms | 32.0 | 0 | 77,856 | 30.0 s |
| Sustained decode | 0 | 64 | Valid | 3,263.4 | 52.0 | 467 ms | 19.2 ms | 64.0 | 0 | 97,856 | 30.0 s |
| Sustained decode | 0 | 128 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 16K | 1 | Valid | 163.4 | 163.8 | 79 ms | 6.1 ms | 1.0 | 0 | 4,902 | 30.0 s |
| Sustained decode | 16K | 2 | Valid | 281.4 | 141.0 | 109 ms | 7.1 ms | 2.0 | 0 | 8,440 | 30.0 s |
| Sustained decode | 16K | 4 | Valid | 508.0 | 127.4 | 175 ms | 7.9 ms | 4.0 | 0 | 15,236 | 30.0 s |
| Sustained decode | 16K | 8 | Valid | 812.0 | 101.5 | 297 ms | 9.8 ms | 8.0 | 0 | 24,361 | 30.0 s |
| Sustained decode | 16K | 16 | Valid | 1,132.7 | 70.3 | 585 ms | 14.2 ms | 16.0 | 0 | 33,968 | 30.0 s |
| Sustained decode | 16K | 32 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 16K | 64 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 16K | 128 | Over capacity | — | — | — | — | — | — | — | — |
| Sustained decode | 32K | 1 | Valid | 149.1 | 149.4 | 77 ms | 6.7 ms | 1.0 | 0 | 4,472 | 30.0 s |
| Sustained decode | 32K | 2 | Valid | 243.6 | 122.0 | 95 ms | 8.2 ms | 2.0 | 0 | 7,307 | 30.0 s |
| Sustained decode | 32K | 4 | Valid | 422.3 | 105.9 | 146 ms | 9.4 ms | 4.0 | 0 | 12,668 | 30.0 s |
| Sustained decode | 32K | 8 | Valid | 625.4 | 78.3 | 234 ms | 12.8 ms | 8.0 | 0 | 18,760 | 30.0 s |
| 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 | 126.8 | 127.0 | 133 ms | 7.9 ms | 1.0 | 0 | 3,804 | 30.0 s |
| Sustained decode | 64K | 2 | Valid | 192.2 | 96.2 | 168 ms | 10.4 ms | 2.0 | 0 | 5,764 | 30.0 s |
| Sustained decode | 64K | 4 | Valid | 312.9 | 78.4 | 254 ms | 12.8 ms | 4.0 | 0 | 9,384 | 30.0 s |
| 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 | 97.5 | 97.7 | 355 ms | 10.2 ms | 1.0 | 0 | 2,925 | 30.0 s |
| Sustained decode | 128K | 2 | Valid | 135.0 | 67.4 | 434 ms | 14.8 ms | 2.0 | 0 | 4,048 | 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 | Valid | 67.9 | 68.0 | 706 ms | 14.7 ms | 1.0 | 0 | 2,038 | 30.0 s |
| Sustained decode | 248K | 2 | Valid | 86.7 | 43.2 | 864 ms | 23.1 ms | 2.0 | 0 | 2,600 | 30.0 s |
| 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 | — | — | — | — | — | — | — | — |
Over capacity: not run because this many requests at this context would exceed the server's KV cache.