LLMBoost: Make Large Language Models Stronger with Boosting
Zehao Chen, Tianxiang Ai, Yifei Li, Gongxun Li, Yuyang Wei, Wang Zhou, Guanghui Li, Bin Yu, Zhijun Chen, Hailong Sun, Fuzhen Zhuang, Jianxin Li, Deqing Wang, Yikun Ban
TL;DR
LLMBoost advances ensemble learning for large language models by moving beyond black-box output fusion to exploit internal representations. It introduces a cross-model attention mechanism that allows successors to fuse predecessors’ hidden states, a chain training paradigm with an error-suppression objective for progressive correction, and a near-parallel inference scheme that pipelines states across models to reduce latency. The authors establish theoretical guarantees for monotonic improvement under bounded correction and demonstrate empirical gains on commonsense and arithmetic reasoning benchmarks, with notable latency reductions and competitive memory use. The results suggest a practical path to more accurate and efficient multi-LLM systems, including industrial tool-scheduling applications like CCAD.
Abstract
Ensemble learning of LLMs has emerged as a promising alternative to enhance performance, but existing approaches typically treat models as black boxes, combining the inputs or final outputs while overlooking the rich internal representations and interactions across models.In this work, we introduce LLMBoost, a novel ensemble fine-tuning framework that breaks this barrier by explicitly leveraging intermediate states of LLMs. Inspired by the boosting paradigm, LLMBoost incorporates three key innovations. First, a cross-model attention mechanism enables successor models to access and fuse hidden states from predecessors, facilitating hierarchical error correction and knowledge transfer. Second, a chain training paradigm progressively fine-tunes connected models with an error-suppression objective, ensuring that each model rectifies the mispredictions of its predecessor with minimal additional computation. Third, a near-parallel inference paradigm design pipelines hidden states across models layer by layer, achieving inference efficiency approaching single-model decoding. We further establish the theoretical foundations of LLMBoost, proving that sequential integration guarantees monotonic improvements under bounded correction assumptions. Extensive experiments on commonsense reasoning and arithmetic reasoning tasks demonstrate that LLMBoost consistently boosts accuracy while reducing inference latency.
