Qwen3.6-35B-A3B · vLLM · FP8 + MTP

status: done

Configuration

ModelQwen/Qwen3.6-35B-A3B
CompanyAlibaba
FamilyQwen
Parameters35B / 3B (MoE)
EnginevLLM + MTP (speculative decoding)
Quant / precisionFP8
Why this quantQwen3.6-35B-A3B FP8 + the model's native MTP module (mtp.safetensors ships in-repo) — built-in multi-token-prediction speculative decoding on the sparse MoE.
DownloadQwen/Qwen3.6-35B-A3B-FP8
Context window65536
Input modalitiestext, image (served text-only here)

Measured results

Prefill tok/s420.12
Decode tok/s407.93
Peak memory (GB)106.55 (system MemAvailable delta (10s sampling) — vLLM static KV reservation (util 0.85) + MTP head)
Completed2026-06-22 19:28 +08

Full run command

# planned: base Qwen3.6-35B-A3B-FP8 + native MTP via vLLM --speculative-config (method finalized at
# run time; qwen3.6 ships mtp.safetensors in-repo).
docker run -d --gpus all --ipc=host -p 8000:8000 \
  -v ~/.cache/huggingface:/root/.cache/huggingface --env HF_TOKEN=*** \
  vllm/vllm-openai:cu130-nightly Qwen/Qwen3.6-35B-A3B-FP8 \
  --host 0.0.0.0 --port 8000 --max-model-len 65536 --gpu-memory-utilization 0.85 --max-num-seqs 32 \
  --speculative-config '{"method":"mtp","num_speculative_tokens":3}'

qwen3.6-35b-a3b Alibaba Qwen FP8 16-40B conc-32

Notes

Native MTP lifts the Qwen3.6 MoE +43% — a clean win, and acceptance matches the dense 27B. Qwen3.6-35B-A3B FP8 + the model’s built-in MTP head, on vLLM.

  • Workload: ShareGPT V3, concurrency 32. 1000/1000, 0 errors in 627 s — clean, no time cap.
  • Throughput (aggregate, conc 32): prefill 420.1 tok/s, decode 407.9 tok/s vs the base Qwen3.6-35B-A3B’s 286.0+43% decode from MTP.
  • Acceptance rate (captured from vLLM SpecDecoding metrics): mean acceptance length ≈ 3.0, avg draft acceptance ≈ 67%, per-position 0.84 / 0.66 / 0.51 — essentially identical to the dense Qwen3.6-27B MTP (67%), which is expected: acceptance is workload-driven (this ShareGPT chat load), not model-size-driven. It sits a bit under the ~80%+ Qwen reports on coding workloads — general chat is less predictable per token. (Cross-checked against published MTP rates per CLAUDE.md.)
  • A smaller % gain than the dense 27B (+43% vs +56%) — and that’s the headroom story again. The MoE base is already fast (286 vs the dense 27B’s 155) because it activates only ~3B params, so there’s less idle compute at conc 32 for the MTP draft to convert into throughput. Same ~67% acceptance, smaller relative lift — the faster the base, the less spec-decode adds at a given concurrency. Both Qwen3.6 models still win clearly at conc 32, unlike the saturated 120B gpt-oss.
  • Memory: 106.6 GB is the vLLM --gpu-memory-utilization 0.85 reservation (+ MTP head), not the footprint (FP8 weights ≈ 35 GB).