Arbitrage: Efficient Reasoning via Advantage-Aware Speculation

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Maheswaran, Monishwaran, Tiwari, Rishabh, Hu, Yuezhou, Dilmen, Kerem, Hooper, Coleman, Xi, Haocheng, Lee, Nicholas, Farajtabar, Mehrdad, Mahoney, Michael W., Keutzer, Kurt, Gholami, Amir
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866918239582289920
author Maheswaran, Monishwaran
Tiwari, Rishabh
Hu, Yuezhou
Dilmen, Kerem
Hooper, Coleman
Xi, Haocheng
Lee, Nicholas
Farajtabar, Mehrdad
Mahoney, Michael W.
Keutzer, Kurt
Gholami, Amir
author_facet Maheswaran, Monishwaran
Tiwari, Rishabh
Hu, Yuezhou
Dilmen, Kerem
Hooper, Coleman
Xi, Haocheng
Lee, Nicholas
Farajtabar, Mehrdad
Mahoney, Michael W.
Keutzer, Kurt
Gholami, Amir
contents Modern Large Language Models achieve impressive reasoning capabilities with long Chain of Thoughts, but they incur substantial computational cost during inference, and this motivates techniques to improve the performance-cost ratio. Among these techniques, Speculative Decoding accelerates inference by employing a fast but inaccurate draft model to autoregressively propose tokens, which are then verified in parallel by a more capable target model. However, due to unnecessary rejections caused by token mismatches in semantically equivalent steps, traditional token-level Speculative Decoding struggles in reasoning tasks. Although recent works have shifted to step-level semantic verification, which improve efficiency by accepting or rejecting entire reasoning steps, existing step-level methods still regenerate many rejected steps with little improvement, wasting valuable target compute. To address this challenge, we propose Arbitrage, a novel step-level speculative generation framework that routes generation dynamically based on the relative advantage between draft and target models. Instead of applying a fixed acceptance threshold, Arbitrage uses a lightweight router trained to predict when the target model is likely to produce a meaningfully better step. This routing approximates an ideal Arbitrage Oracle that always chooses the higher-quality step, achieving near-optimal efficiency-accuracy trade-offs. Across multiple mathematical reasoning benchmarks, Arbitrage consistently surpasses prior step-level Speculative Decoding baselines, reducing inference latency by up to $\sim2\times$ at matched accuracy.
format Preprint
id arxiv_https___arxiv_org_abs_2512_05033
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Arbitrage: Efficient Reasoning via Advantage-Aware Speculation
Maheswaran, Monishwaran
Tiwari, Rishabh
Hu, Yuezhou
Dilmen, Kerem
Hooper, Coleman
Xi, Haocheng
Lee, Nicholas
Farajtabar, Mehrdad
Mahoney, Michael W.
Keutzer, Kurt
Gholami, Amir
Computation and Language
Artificial Intelligence
Machine Learning
Modern Large Language Models achieve impressive reasoning capabilities with long Chain of Thoughts, but they incur substantial computational cost during inference, and this motivates techniques to improve the performance-cost ratio. Among these techniques, Speculative Decoding accelerates inference by employing a fast but inaccurate draft model to autoregressively propose tokens, which are then verified in parallel by a more capable target model. However, due to unnecessary rejections caused by token mismatches in semantically equivalent steps, traditional token-level Speculative Decoding struggles in reasoning tasks. Although recent works have shifted to step-level semantic verification, which improve efficiency by accepting or rejecting entire reasoning steps, existing step-level methods still regenerate many rejected steps with little improvement, wasting valuable target compute. To address this challenge, we propose Arbitrage, a novel step-level speculative generation framework that routes generation dynamically based on the relative advantage between draft and target models. Instead of applying a fixed acceptance threshold, Arbitrage uses a lightweight router trained to predict when the target model is likely to produce a meaningfully better step. This routing approximates an ideal Arbitrage Oracle that always chooses the higher-quality step, achieving near-optimal efficiency-accuracy trade-offs. Across multiple mathematical reasoning benchmarks, Arbitrage consistently surpasses prior step-level Speculative Decoding baselines, reducing inference latency by up to $\sim2\times$ at matched accuracy.
title Arbitrage: Efficient Reasoning via Advantage-Aware Speculation
topic Computation and Language
Artificial Intelligence
Machine Learning
url https://arxiv.org/abs/2512.05033