DSpine

Draft in Parallel, Condition Through Depth: Adjacent Causal Injection for Speculative Decoding

DSpine is a parallel drafter for speculative decoding. At every draft layer, each position receives the predicted feature of its predecessor, so the causal chain unfolds over network depth while all positions are still drafted in parallel.

DSpine overview

News

[2026-10] Inference code released.
[2026-09] Paper released on arXiv.

Results

Acceptance length on Qwen3-8B. DSpine, DSpark and DFlash2 are all retrained on Open-PerfectBlend with the same configuration.

Temp.	Method	GSM8K	MATH-500	HumanEval	MBPP	LCB	MT-Bench	Arena-Hard	Avg.
T = 0	DFlash^†	6.32	7.99	6.56	6.29	6.11	4.26	3.91	5.92
	Domino^†	9.68	9.40	7.23	6.89	6.40	5.12	4.65	7.05
	DSpark	10.00	9.88	7.78	7.35	6.81	5.39	4.87	7.44
	DFlash2	10.06	10.04	7.99	7.33	6.96	5.40	5.06	7.55
	DSpine	10.55	10.30	8.27	7.66	7.25	5.63	5.13	7.83
T = 1	DFlash^†	5.75	6.51	5.52	5.23	4.53	3.77	3.25	4.94
	Domino^†	8.01	7.13	5.89	5.56	4.59	4.36	3.61	5.59
	DSpark	9.33	8.64	6.91	6.66	5.78	4.99	4.25	6.65
	DFlash2	9.07	8.42	6.99	6.43	5.67	4.90	4.25	6.53
	DSpine	9.83	8.99	7.39	6.97	6.11	5.09	4.49	6.98

^† Official checkpoints: z-lab/Qwen3-8B-DFlash-b16 and Huang2020/Qwen3-8B-Domino-b16.

Installation

git clone https://github.com/tencent/dspine.git
cd dspine
pip install -e .

Usage

The server settings below are the ones behind the acceptance lengths and throughput reported in the paper.

sglang serve \
  --model-path Qwen/Qwen3-8B \
  --speculative-algorithm DSPINE \
  --speculative-draft-model-path <dspine-model-path> \
  --speculative-num-draft-tokens 16 \
  --dtype bfloat16 \
  --attention-backend fa3 \
  --page-size 1 \
  --mem-fraction-static 0.65 \
  --context-length 8192 \
  --max-running-requests 64 \
  --cuda-graph-bs-decode 1 2 4 8 16 32 64 \
  --trust-remote-code

Roadmap

☐ Training code for DSpine
☐ DSpine for Qwen3.8-27B

Acknowledgements

We thank DFlash, SpecForge, SGLang and FlashInfer for their open-source work.

Citation

@article{zhang2026dspine,
  title   = {Draft in Parallel, Condition Through Depth: Adjacent Causal Injection for Speculative Decoding},
  author  = {Zhang, Haohui and Chen, Keyu and Sun, Haocheng and Gu, Weibo and Qiao, Ruizhi and Sun, Xing and Jiang, Bo},
  journal = {arXiv preprint arXiv:2609.36173},
  year    = {2026}
}