The paper examines lossy verification techniques used in speculative decoding for large language models, showing that many methods can be grouped into truncation-based and collaborative verification categories. It analyzes how these approaches alter the decoding distribution, revealing that truncation-based methods can significantly degrade performance due to distributional distortion, while collaborative methods depend more on overshoot suppression and supervision quality than on simple interpolation between draft and target models. A diagnostic evaluation framework is introduced to assess these failure modes across curated benchmarks.
By Tianyu Wang, Yuxuan Zhou, Heng Li, Wenbin Wang, Zikai Xiao, Chunrui Zheng, Junyuan Shang
The efficiency of Large Language Model (LLM) serving is fundamentally limited by the sequential nature of autoregressive decoding. Speculative Decoding (SD) mitigates this by using a lightweight draft...
ResiSpec is a framework that improves speculative decoding for large language models by reshaping the residual distribution during verification. It addresses the problem of residual drift, where rejected candidates cause the target distribution to diverge from the draft model’s predictions, rendering later candidates ineffective. By aligning the verification process with the draft model’s high‑confidence regions, ResiSpec prevents candidate obsolescence and achieves up to 1.92× speedup over existing multi‑candidate methods.
By Zhi-Kai Chen, Jun-Jie Tao, Wei-Xiang Mao, De-Chuan Zhan, Han-Jia Ye
arXiv:2607. 08690v1 Announce Type: cross Abstract: Speculative decoding accelerates sampling from an autoregressive LLM by using a faster auxiliary model to draft tokens which are then verified in parallel by the LLM.
By Guoxuan Xia, Luka Ribar, Paul Balanca
arXiv:2608. 08721v1 Announce Type: cross Abstract: Speculative decoding accelerates large language model inference by drafting multiple tokens for parallel verification, with efficiency critically determined by the speculative length selected at each decoding round.
By Zexun Lin, Yuan Feng, Junlin Lv, Kevin S. Zhou, Xike Xie
Speculative decoding accelerates sampling from an autoregressive LLM by using a faster auxiliary model to draft tokens which are then verified in parallel by the LLM. Standard speculative decoding is lossless: its rejection and resampling steps exactly preserve the LLM's sampling distribution.