Whole-family linear-attention NVFP4 reaches 102.76 tok/s at c16
Question. Does the accepted whole-family linear-attention NVFP4 map retain production throughput on healthy hardware while reducing c16 weight traffic?
| setup | |
|---|---|
| nodes | gx10-5e36 head and gx10-2a13 worker, GB10, 6.17.13-rocket64k, 64 KiB pages |
| checkpoint | nvidia/Qwen3.8-Flash-Next-NVFP4 at fc694b54fb0174e0913e6adf86691ef85a4ead47 |
| Rocket commit | 422cde89c250d3fa8a8c0bd7800ebbbb52b085c6 |
| vLLM image | vllm/vllm-openai:qwen38-flash-next at sha256:d464f3b466fa9c45ddbff8a812e80564503b6879a9fd95c1a47514f3f0df5a4a |
| runtime source | MiaAI-Lab Qwen3.8 dual-Spark at c2325b22602b51a5faf55fc2bebccc34f3f80b9f |
| serving map | 180 base linear-attention projections in W4A4 NVFP4 |
| artifact | 64539e4a...56c4e5 |
| runtime | TP2, EP, MTP3, FP8 KV cache, 262,144-token context, vLLM |
This path required a model-specific 180-tensor overlay, ModelOpt block-16 packing, and separate FP8 dispatch for MTP experts.
scripts/numerics/qwen38-expanded-calibration.sh \
--output-dir /home/glwillen/calibration/qwen38-linear-nvfp4-production-20260907-06 \
--nvfp4-artifact-dir /home/glwillen/calibration/qwen38-linear-nvfp4-artifacts/64539e4a5a4b533aa143d20e055ae73ebd10b21f05dbd422847a9be30e56c4e5 \
--production
jq -r '.[] | [.concurrency,.aggregate_tok_s,.per_stream_tok_s,.mean_ttft_s] | @tsv' \
/home/glwillen/calibration/qwen38-linear-nvfp4-production-20260907-06/throughput.json1 41.216281042312566 41.216281042312566 5.85900435000076
2 72.77877253307481 36.97938550701514 5.90815700299936
4 70.11521222444112 28.345566091688937 5.998136556499958
8 93.19815126912113 19.738601543822398 9.338284739500068
16 102.7641806133714 11.711004318437539 16.682225616625374
| concurrency | aggregate throughput | per-stream throughput | mean TTFT |
|---|---|---|---|
| 1 | 41.22 tok/s | 41.22 tok/s/stream | 5.859 s |
| 2 | 72.78 tok/s | 36.98 tok/s/stream | 5.908 s |
| 4 | 70.12 tok/s | 28.35 tok/s/stream | 5.998 s |
| 8 | 93.20 tok/s | 19.74 tok/s/stream | 9.338 s |
| 16 | 102.76 tok/s | 11.71 tok/s/stream | 16.682 s |
nvidia-smi --query-gpu=clocks.current.sm,power.draw,utilization.gpu --format=csv,noheader
ssh glwillen@192.168.100.11 'nvidia-smi --query-gpu=clocks.current.sm,power.draw,utilization.gpu --format=csv,noheader'head: 2483 MHz, 36.01 W, 95 %
worker: 2463 MHz, 35.94 W, 95 %
| matched healthy c16 result | FP8 | NVFP4 | NVFP4 delta |
|---|---|---|---|
| aggregate throughput | 101.40 tok/s | 102.76 tok/s | +1.34% |
| per-stream throughput | 11.58 tok/s/stream | 11.71 tok/s/stream | +1.10% |
| mean TTFT | 16.822 s | 16.682 s | -0.140 s |
| traffic removed from BF16 | 2,085,027,840 bytes/step | 2,997,226,080 bytes/step | +912,198,240 bytes/step |
One NVFP4 ladder and one matched healthy FP8 ladder were measured. Run-to-run variance was not measured.
Verdict. Accepted for the serving-weight map. All 180 base linear-attention projections remain NVFP4 because the map removes 2,997,226,080 bytes per c16 step and holds c16 throughput within a 1.34% gain over the healthy FP8 control.
This vLLM result is a comparison baseline. At c16 it reaches 32.1% of Rocket’s greater-than-320 aggregate tok/s target and 58.6% of the greater-than-20 generated tok/s/stream target.
Next.
- rank the remaining BF16 and FP8 families by measured c16 traffic
- taper MTP depth from measured acceptance by concurrency
- retain family-isolated telemetry for every serving-weight conversion
Reopen if.
- NVIDIA publishes a checkpoint revision or ModelOpt NVFP4 ABI change
- an upstream vLLM release changes the Qwen3.8 NVFP4 or MTP execution path
- a driver, firmware, or hardware change moves the healthy GB10 clock range