Speed test matrix

Qwen3.5-0.8B-Base on H200 NVL 141GB

sglang · 0.5.6.post3.dev9160+g1cf2b8c54 · BF166 contexts (8K–251K) × 8 concurrency levels (1–128) · prefill at 8K, 16K, 32K, 64K, 128K, 251K, 256K

by @keennaylmx dev importMeasured Aug 29, 2026, 16:51 UTC

Hardware

Type: Discrete GPU
GPU: H200 NVL
VRAM: 141 GB
OS: linux

Engine

Engine: sglang
Version: 0.5.6.post3.dev9160+g1cf2b8c54
Quantization: BF16
Backend: cuda
Repository: github.com/sgl-project/sglang
Build: cuda-13.2
Commit: 1cf2b8c54d81

Run

Served model: qwen
Revision: main
Benchmark tool: llm-inference-bench v0.4.29
Decode test: Fixed duration
Prefill mode: Measured during decode warm-up
Time per measurement: 30 s
Max output: 4,096 tokens

Launch command

env SGLANG_ALLOW_OVERWRITE_LONGER_CONTEXT_LEN=1 "$HOME/env_h200-qwen-sglang/bin/sglang" serve --model-path Qwen/Qwen3.5-0.8B-Base --served-model-name qwen --trust-remote-code --tp 1 --reasoning-parser qwen3 --tool-call-parser qwen3_coder --context-length 262144 --mem-fraction-static 0.776885 --enable-metrics --host 0.0.0.0 --port 8000 --api-key <redacted> --mamba-radix-cache-strategy extra_buffer --speculative-algorithm EAGLE --speculative-num-steps 3 --speculative-eagle-topk 1 --speculative-num-draft-tokens 4

Prefill

prompt tok/s by context length

8K context75.1K109 ms TTFT

16K context98.2K164 ms TTFT

32K context97.6K329 ms TTFT

64K context89.6K715 ms TTFT

128K context71.7K1,785 ms TTFT

251K context50.6K4,960 ms TTFT

256K context50.7K5,049 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	403.880 ms TTFT	810.182 ms TTFT	1,526.980 ms TTFT	2,662.178 ms TTFT	4,158.476 ms TTFT	5,199.7407 ms TTFT	Not run	Not run
16K	402.4100 ms TTFT	628.7111 ms TTFT	1,517.694 ms TTFT	2,478.699 ms TTFT	3,735.2124 ms TTFT	4,311.4688 ms TTFT	Not run	Not run
32K	396.1170 ms TTFT	485.6177 ms TTFT	1,378.0158 ms TTFT	2,251.1176 ms TTFT	2,760.0958 ms TTFT	3,304.53,953 ms TTFT	Not run	Not run
64K	393.5283 ms TTFT	637.8384 ms TTFT	1,181.6293 ms TTFT	1,813.3802 ms TTFT	2,129.54,079 ms TTFT	1,884.09,895 ms TTFT	Not run	Over capacity
128K	329.4494 ms TTFT	236.4981 ms TTFT	919.31,430 ms TTFT	1,359.02,284 ms TTFT	1,248.27,495 ms TTFT	1,511.915,067 ms TTFT	Over capacity	Over capacity
251K	274.4966 ms TTFT	83.31,969 ms TTFT	432.73,836 ms TTFT	820.87,876 ms TTFT	782.415,647 ms TTFT	Over capacity	Over capacity	Over capacity

Over capacity: not run because this many requests at this context would exceed the server's KV cache. Not run: the benchmark skipped this measurement during the run, or the run stopped early.

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	75.1K	—	109 ms	—	—	1	—	—
Prefill	16K	1	Valid	98.2K	—	164 ms	—	—	1	—	—
Prefill	32K	1	Valid	97.6K	—	329 ms	—	—	1	—	—
Prefill	64K	1	Valid	89.6K	—	715 ms	—	—	1	—	—
Prefill	128K	1	Valid	71.7K	—	1,785 ms	—	—	1	—	—
Prefill	251K	1	Valid	50.6K	—	4,960 ms	—	—	1	—	—
Prefill	256K	1	Valid	50.7K	—	5,049 ms	—	—	1	—	—
Sustained decode	8K	1	Valid	403.8	412.7	80 ms	2.4 ms	1.0	3	12,113	30.0 s
Sustained decode	8K	2	Valid	810.1	414.4	82 ms	2.4 ms	2.1	6	24,301	30.0 s
Sustained decode	8K	4	Valid	1,526.9	394.0	80 ms	2.5 ms	4.1	12	45,807	30.0 s
Sustained decode	8K	8	Valid	2,662.1	333.4	78 ms	3.0 ms	8.4	17	79,864	30.0 s
Sustained decode	8K	16	Valid	4,158.4	265.2	76 ms	3.8 ms	16.1	32	124,754	30.0 s
Sustained decode	8K	32	Valid	5,199.7	173.3	407 ms	5.8 ms	39.7	32	155,995	30.0 s
Sustained decode	8K	64	Not run	—	—	—	—	—	—	—	—
Sustained decode	8K	128	Not run	—	—	—	—	—	—	—	—
Sustained decode	16K	1	Valid	402.4	403.5	100 ms	2.5 ms	0.9	3	12,071	30.0 s
Sustained decode	16K	2	Valid	628.7	373.1	111 ms	2.7 ms	11.0	4	18,859	30.0 s
Sustained decode	16K	4	Valid	1,517.6	392.9	94 ms	2.5 ms	3.9	12	45,528	30.0 s
Sustained decode	16K	8	Valid	2,478.6	316.7	99 ms	3.2 ms	8.3	16	74,359	30.0 s
Sustained decode	16K	16	Valid	3,735.2	231.0	124 ms	4.3 ms	16.4	19	112,052	30.0 s
Sustained decode	16K	32	Valid	4,311.4	146.7	688 ms	6.8 ms	34.0	32	129,348	30.0 s
Sustained decode	16K	64	Not run	—	—	—	—	—	—	—	—
Sustained decode	16K	128	Not run	—	—	—	—	—	—	—	—
Sustained decode	32K	1	Valid	396.1	393.4	170 ms	2.5 ms	1.0	3	11,882	30.0 s
Sustained decode	32K	2	Valid	485.6	387.6	177 ms	2.6 ms	20.8	3	14,569	30.0 s
Sustained decode	32K	4	Valid	1,378.0	340.9	158 ms	2.9 ms	4.1	10	41,339	30.0 s
Sustained decode	32K	8	Valid	2,251.1	285.1	176 ms	3.5 ms	8.3	17	67,529	30.0 s
Sustained decode	32K	16	Valid	2,760.0	199.1	958 ms	5.0 ms	19.2	16	82,805	30.0 s
Sustained decode	32K	32	Valid	3,304.5	109.3	3,953 ms	9.1 ms	38.8	2	99,140	30.0 s
Sustained decode	32K	64	Not run	—	—	—	—	—	—	—	—
Sustained decode	32K	128	Not run	—	—	—	—	—	—	—	—
Sustained decode	64K	1	Valid	393.5	414.0	283 ms	2.4 ms	1.0	3	11,805	30.0 s
Sustained decode	64K	2	Valid	637.8	331.7	384 ms	3.0 ms	2.5	4	19,134	30.0 s
Sustained decode	64K	4	Valid	1,181.6	313.8	293 ms	3.2 ms	3.9	8	35,449	30.0 s
Sustained decode	64K	8	Valid	1,813.3	228.9	802 ms	4.4 ms	8.3	9	54,393	30.0 s
Sustained decode	64K	16	Valid	2,129.5	162.0	4,079 ms	6.2 ms	16.1	16	63,769	29.9 s
Sustained decode	64K	32	Valid	1,884.0	72.4	9,895 ms	13.8 ms	47.1	0	56,500	30.0 s
Sustained decode	64K	64	Not run	—	—	—	—	—	—	—	—
Sustained decode	64K	128	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	128K	1	Valid	329.4	357.6	494 ms	2.8 ms	1.0	2	9,881	30.0 s
Sustained decode	128K	2	Valid	236.4	111.6	981 ms	9.0 ms	23.6	0	7,091	30.0 s
Sustained decode	128K	4	Valid	919.3	246.2	1,430 ms	4.1 ms	3.9	4	27,577	30.0 s
Sustained decode	128K	8	Valid	1,359.0	191.5	2,284 ms	5.2 ms	7.9	8	40,764	30.0 s
Sustained decode	128K	16	Valid	1,248.2	84.8	7,495 ms	11.8 ms	18.8	0	37,444	30.0 s
Sustained decode	128K	32	Valid	1,511.9	56.7	15,067 ms	17.6 ms	35.5	0	45,338	30.0 s
Sustained decode	128K	64	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	128K	128	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	251K	1	Valid	274.4	295.2	966 ms	3.4 ms	0.9	2	8,232	30.0 s
Sustained decode	251K	2	Valid	83.3	43.0	1,969 ms	23.3 ms	33.5	0	2,498	30.0 s
Sustained decode	251K	4	Valid	432.7	102.3	3,836 ms	9.8 ms	12.0	0	12,980	30.0 s
Sustained decode	251K	8	Valid	820.8	130.0	7,876 ms	7.7 ms	7.8	4	24,626	30.0 s
Sustained decode	251K	16	Valid	782.4	63.8	15,647 ms	15.7 ms	20.0	0	23,458	30.0 s
Sustained decode	251K	32	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	251K	64	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	251K	128	Over capacity	—	—	—	—	—	—	—	—

Over capacity: not run because this many requests at this context would exceed the server's KV cache. Not run: the benchmark skipped this measurement during the run, or the run stopped early.