Speed test matrix

GLM-5.3-NVFP4 on H200 SXM 141GB ×8

vllm · 0.29.0 · NVFP47 contexts (8K–507K) × 8 concurrency levels (1–128) · prefill at 8K, 16K, 32K, 64K, 128K, 256K, 507K, 512K

by @keennaylmx dev importMeasured Sep 15, 2026, 14:41 UTC

Hardware

Type: Discrete GPU
GPU: H200 SXM
GPU count: 8
VRAM: 1128 GB (8 × 141 GB)
OS: linux

Engine

Engine: vllm
Version: 0.29.0
Quantization: NVFP4
Backend: cuda
Repository: github.com/vllm-project/vllm
Build: cuda-13.2

Run

Served model: glm
Revision: main
Benchmark tool: llm-inference-bench v0.6.2
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_h200-glm53-vllm-v0290/bin/vllm" serve Inferact/GLM-5.3-NVFP4 --served-model-name glm --tensor-parallel-size 8 --reasoning-parser glm45 --enable-auto-tool-choice --tool-call-parser glm47 --max-model-len 524288 --gpu-memory-utilization 0.88 --host 0.0.0.0 --port 8000 --api-key <redacted> --dtype bfloat16 --kv-cache-dtype bfloat16 --no-enable-flashinfer-autotune

Prefill

prompt tok/s by context length

8K context10.2K803 ms TTFT

16K context10.1K1,605 ms TTFT

32K context9,7903,301 ms TTFT

64K context9,3336,912 ms TTFT

128K context8,51015,146 ms TTFT

256K context7,13136,128 ms TTFT

507K context5,39294,602 ms TTFT

512K context5,36695,987 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	101.350 ms TTFT	188.669 ms TTFT	335.890 ms TTFT	587.9129 ms TTFT	986.1211 ms TTFT	1,561.6314 ms TTFT	Over capacity	Over capacity
16K	101.271 ms TTFT	188.3100 ms TTFT	333.3142 ms TTFT	581.9196 ms TTFT	972.9302 ms TTFT	1,550.2523 ms TTFT	Over capacity	Over capacity
32K	100.9103 ms TTFT	187.9147 ms TTFT	332.9197 ms TTFT	579.2286 ms TTFT	972.8532 ms TTFT	Over capacity	Over capacity	Over capacity
64K	100.4182 ms TTFT	186.6243 ms TTFT	330.9335 ms TTFT	571.0540 ms TTFT	Over capacity	Over capacity	Over capacity	Over capacity
128K	99.3376 ms TTFT	184.2496 ms TTFT	325.0722 ms TTFT	Over capacity	Over capacity	Over capacity	Over capacity	Over capacity
256K	97.7751 ms TTFT	180.01,043 ms TTFT	Over capacity	Over capacity	Over capacity	Over capacity	Over capacity	Over capacity
507K	94.51,784 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	10.2K	—	803 ms	—	—	1	—	—
Prefill	16K	1	Valid	10.1K	—	1,605 ms	—	—	1	—	—
Prefill	32K	1	Valid	9,790.0	—	3,301 ms	—	—	1	—	—
Prefill	64K	1	Valid	9,333.0	—	6,912 ms	—	—	1	—	—
Prefill	128K	1	Valid	8,510.0	—	15,146 ms	—	—	1	—	—
Prefill	256K	1	Valid	7,131.0	—	36,128 ms	—	—	1	—	—
Prefill	507K	1	Valid	5,392.0	—	94,602 ms	—	—	1	—	—
Prefill	512K	1	Valid	5,366.0	—	95,987 ms	—	—	1	—	—
Sustained decode	8K	1	Valid	101.3	101.2	50 ms	9.9 ms	1.0	0	3,037	30.0 s
Sustained decode	8K	2	Valid	188.6	94.3	69 ms	10.6 ms	2.0	0	5,656	30.0 s
Sustained decode	8K	4	Valid	335.8	84.0	90 ms	11.9 ms	4.0	0	10,074	30.0 s
Sustained decode	8K	8	Valid	587.9	73.4	129 ms	13.6 ms	8.0	0	17,632	30.0 s
Sustained decode	8K	16	Valid	986.1	61.7	211 ms	16.2 ms	16.0	0	29,585	30.0 s
Sustained decode	8K	32	Valid	1,561.6	48.9	314 ms	20.5 ms	32.0	0	46,849	30.0 s
Sustained decode	8K	64	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	8K	128	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	16K	1	Valid	101.2	101.2	71 ms	9.9 ms	1.0	0	3,034	30.0 s
Sustained decode	16K	2	Valid	188.3	94.1	100 ms	10.6 ms	2.0	0	5,648	30.0 s
Sustained decode	16K	4	Valid	333.3	83.4	142 ms	12.0 ms	4.0	0	9,996	30.0 s
Sustained decode	16K	8	Valid	581.9	72.8	196 ms	13.7 ms	8.0	0	17,459	30.0 s
Sustained decode	16K	16	Valid	972.9	60.9	302 ms	16.4 ms	16.0	0	29,187	30.0 s
Sustained decode	16K	32	Valid	1,550.2	48.4	523 ms	20.7 ms	32.0	0	46,494	30.0 s
Sustained decode	16K	64	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	16K	128	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	32K	1	Valid	100.9	100.9	103 ms	9.9 ms	1.0	0	3,026	30.0 s
Sustained decode	32K	2	Valid	187.9	94.0	147 ms	10.6 ms	2.0	0	5,636	30.0 s
Sustained decode	32K	4	Valid	332.9	83.3	197 ms	12.0 ms	4.0	0	9,987	30.0 s
Sustained decode	32K	8	Valid	579.2	72.4	286 ms	13.8 ms	8.0	0	17,376	30.0 s
Sustained decode	32K	16	Valid	972.8	60.8	532 ms	16.4 ms	16.0	0	29,186	30.0 s
Sustained decode	32K	32	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	32K	64	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	32K	128	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	64K	1	Valid	100.4	100.5	182 ms	10.0 ms	1.0	0	3,012	30.0 s
Sustained decode	64K	2	Valid	186.6	93.3	243 ms	10.7 ms	2.0	0	5,596	30.0 s
Sustained decode	64K	4	Valid	330.9	82.8	335 ms	12.1 ms	4.0	0	9,924	30.0 s
Sustained decode	64K	8	Valid	571.0	71.4	540 ms	14.0 ms	8.0	0	17,127	30.0 s
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	99.3	99.5	376 ms	10.0 ms	1.0	0	2,980	30.0 s
Sustained decode	128K	2	Valid	184.2	92.2	496 ms	10.8 ms	2.0	0	5,526	30.0 s
Sustained decode	128K	4	Valid	325.0	81.2	722 ms	12.3 ms	4.0	0	9,748	30.0 s
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	256K	1	Valid	97.7	98.0	751 ms	10.2 ms	1.0	0	2,930	30.0 s
Sustained decode	256K	2	Valid	180.0	90.2	1,043 ms	11.1 ms	2.0	0	5,400	30.0 s
Sustained decode	256K	4	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	256K	8	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	256K	16	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	256K	32	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	256K	64	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	256K	128	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	507K	1	Valid	94.5	95.1	1,784 ms	10.5 ms	1.0	0	2,835	30.0 s
Sustained decode	507K	2	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	507K	4	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	507K	8	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	507K	16	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	507K	32	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	507K	64	Over capacity	—	—	—	—	—	—	—	—
Sustained decode	507K	128	Over capacity	—	—	—	—	—	—	—	—

Over capacity: not run because this many requests at this context would exceed the server's KV cache.