Speed test matrix

Qwen3.8-27B on RTX PRO 6000 Blackwell Server Edition 96GB ×2

vllm · 0.30.1rc1.dev452+g73a583112 · BF166 contexts (8K–251K) × 8 concurrency levels (1–128) · prefill at 8K, 16K, 32K, 64K, 128K, 251K, 256K

by @keennaylmx dev importMeasured Oct 15, 2026, 12:02 UTC

Hardware

Type: Discrete GPU
GPU: RTX PRO 6000 Blackwell Server Edition
GPU count: 2
VRAM: 192 GB (2 × 96 GB)
OS: linux

Engine

Engine: vllm
Version: 0.30.1rc1.dev452+g73a583112
Quantization: BF16
Backend: cuda
Repository: github.com/vllm-project/vllm
Build: cuda-13.2
Commit: 73a5831127a9

Run

Served model: qwen
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: 4,096 tokens

Launch command

"$HOME/env_rtxpro6k-qwen-vllm-73a5831127a9/bin/vllm" serve Qwen/Qwen3.8-27B --served-model-name qwen --trust-remote-code --tensor-parallel-size 2 --reasoning-parser qwen3 --enable-auto-tool-choice --tool-call-parser qwen3_coder --max-model-len 262144 --gpu-memory-utilization 0.91 --host 0.0.0.0 --port 8000 --api-key <redacted> --attention-backend FLASH_ATTN --speculative-config '{"method":"mtp","num_speculative_tokens":5}'

Prefill

prompt tok/s by context length

8K context8,440976 ms TTFT

16K context8,4201,932 ms TTFT

32K context8,1213,982 ms TTFT

64K context7,4858,613 ms TTFT

128K context6,40320,107 ms TTFT

251K context5,02050,245 ms TTFT

256K context4,94851,993 ms TTFT

Sustained decode

total tok/s · rows are context length, columns are simultaneous requests

Context	1	2	4	8	16	32	64	128
8K	72.1139 ms TTFT	135.3224 ms TTFT	245.0500 ms TTFT	470.0966 ms TTFT	705.91,115 ms TTFT	1,019.62,078 ms TTFT	1,311.74,036 ms TTFT	1,322.3Requests queued5,999 ms TTFT
16K	56.3236 ms TTFT	123.9364 ms TTFT	205.2868 ms TTFT	406.71,242 ms TTFT	580.62,214 ms TTFT	860.53,691 ms TTFT	1,070.27,213 ms TTFT	Over capacity
32K	46.8250 ms TTFT	95.7399 ms TTFT	186.7863 ms TTFT	341.71,378 ms TTFT	441.81,779 ms TTFT	620.83,971 ms TTFT	Over capacity	Over capacity
64K	31.88,640 ms TTFT	68.38,932 ms TTFT	133.21,109 ms TTFT	248.51,898 ms TTFT	294.33,318 ms TTFT	Over capacity	Over capacity	Over capacity
128K	23.4547 ms TTFT	41.9795 ms TTFT	79.31,279 ms TTFT	164.32,085 ms TTFT	Over capacity	Over capacity	Over capacity	Over capacity
251K	14.0760 ms TTFT	25.41,188 ms TTFT	49.22,047 ms TTFT	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. 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	8,440.0	—	976 ms	—	—	1	—	—
Prefill	16K	1	Valid	8,420.0	—	1,932 ms	—	—	1	—	—
Prefill	32K	1	Valid	8,121.0	—	3,982 ms	—	—	1	—	—
Prefill	64K	1	Valid	7,485.0	—	8,613 ms	—	—	1	—	—
Prefill	128K	1	Valid	6,403.0	—	20,107 ms	—	—	1	—	—
Prefill	251K	1	Valid	5,020.0	—	50,245 ms	—	—	1	—	—
Prefill	256K	1	Valid	4,948.0	—	51,993 ms	—	—	1	—	—
Sustained decode	8K	1	Valid	72.1	73.3	139 ms	13.6 ms	1.0	0	2,162	30.0 s
Sustained decode	8K	2	Valid	135.3	68.1	224 ms	14.7 ms	2.0	0	4,055	30.0 s
Sustained decode	8K	4	Valid	245.0	62.1	500 ms	16.1 ms	4.0	0	7,344	30.0 s
Sustained decode	8K	8	Valid	470.0	59.5	966 ms	16.8 ms	8.0	0	14,088	30.0 s
Sustained decode	8K	16	Valid	705.9	45.0	1,115 ms	22.2 ms	16.0	0	21,171	30.0 s
Sustained decode	8K	32	Valid	1,019.6	31.9	2,078 ms	31.4 ms	32.0	0	30,540	30.0 s
Sustained decode	8K	64	Valid	1,311.7	20.2	4,036 ms	49.6 ms	64.0	0	39,288	30.0 s
Sustained decode	8K	128	Requests queued	1,322.3	13.2	5,999 ms	76.0 ms	99.2	0	39,584	29.9 s
Sustained decode	16K	1	Valid	56.3	58.1	236 ms	17.2 ms	1.0	0	1,690	30.0 s
Sustained decode	16K	2	Valid	123.9	62.7	364 ms	15.9 ms	2.0	0	3,713	30.0 s
Sustained decode	16K	4	Valid	205.2	52.3	868 ms	19.1 ms	4.0	0	6,150	30.0 s
Sustained decode	16K	8	Valid	406.7	52.0	1,242 ms	19.2 ms	8.0	0	12,182	30.0 s
Sustained decode	16K	16	Valid	580.6	36.4	2,214 ms	27.5 ms	16.0	0	17,401	30.0 s
Sustained decode	16K	32	Valid	860.5	26.3	3,691 ms	38.1 ms	32.0	0	25,780	30.0 s
Sustained decode	16K	64	Valid	1,070.2	15.5	7,213 ms	64.7 ms	64.0	0	32,006	29.9 s
Sustained decode	16K	128	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	32K	1	Valid	46.8	48.4	250 ms	20.7 ms	1.0	0	1,403	30.0 s
Sustained decode	32K	2	Valid	95.7	49.1	399 ms	20.4 ms	2.0	0	2,868	30.0 s
Sustained decode	32K	4	Valid	186.7	47.2	863 ms	21.2 ms	4.0	0	5,598	30.0 s
Sustained decode	32K	8	Valid	341.7	43.2	1,378 ms	23.1 ms	8.0	0	10,241	30.0 s
Sustained decode	32K	16	Valid	441.8	27.8	1,779 ms	36.0 ms	16.0	0	13,218	29.9 s
Sustained decode	32K	32	Valid	620.8	19.1	3,971 ms	52.2 ms	32.0	0	18,618	30.0 s
Sustained decode	32K	64	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	32K	128	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	64K	1	Valid	31.8	32.8	8,640 ms	30.5 ms	1.0	0	951	30.0 s
Sustained decode	64K	2	Valid	68.3	35.3	8,932 ms	28.3 ms	2.0	0	2,045	29.9 s
Sustained decode	64K	4	Valid	133.2	33.9	1,109 ms	29.5 ms	4.0	0	3,986	29.9 s
Sustained decode	64K	8	Valid	248.5	32.4	1,898 ms	30.9 ms	8.0	0	7,452	30.0 s
Sustained decode	64K	16	Valid	294.3	18.9	3,318 ms	52.8 ms	16.0	0	8,809	29.9 s
Sustained decode	64K	32	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	64K	64	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	64K	128	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	128K	1	Valid	23.4	24.5	547 ms	40.8 ms	1.0	0	702	29.9 s
Sustained decode	128K	2	Valid	41.9	22.2	795 ms	45.1 ms	2.0	0	1,253	29.9 s
Sustained decode	128K	4	Valid	79.3	20.8	1,279 ms	48.0 ms	4.0	0	2,377	30.0 s
Sustained decode	128K	8	Valid	164.3	21.4	2,085 ms	46.6 ms	8.0	0	4,927	30.0 s
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	251K	1	Valid	14.0	15.2	760 ms	65.7 ms	1.0	0	419	30.0 s
Sustained decode	251K	2	Valid	25.4	13.9	1,188 ms	71.7 ms	2.0	0	762	30.0 s
Sustained decode	251K	4	Valid	49.2	13.1	2,047 ms	76.1 ms	4.0	0	1,469	29.9 s
Sustained decode	251K	8	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	251K	16	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	251K	32	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	251K	64	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	251K	128	Over capacity	—	—	—	—	—	—	—	—

Requests queued: the server could not run all requests at once, so some waited in a queue. Over capacity: not run because this many requests at this context would exceed the server's KV cache.