GatePro: Parameter-Free Expert Selection Optimization for Mixture-of-Experts Models
Chen Zheng, Yuhang Cai, Deyi Liu, Jin Ma, Yiyuan Ma, Yuan Yang, Jing Liu, Yutao Zeng, Xun Zhou, Siyuan Qiao
TL;DR
GatePro introduces a parameter-free, hot-swappable mechanism to boost diversity among experts in Mixture-of-Experts models by enforcing localized competition between functionally similar experts. It computes a gating-similarity matrix from gating weights, identifies the most similar expert pairs, and applies token-specific competition with a small logit penalty to suppress redundant co-activations, thereby increasing selection entropy and distinctiveness without adding parameters. Across multiple model scales and training phases, GatePro yields consistent gains in reasoning and knowledge tasks, accelerates expert activation, and reduces redundancy, with pronounced effects in deeper layers. The method demonstrates practical applicability, scalability with larger expert pools, and persistent improvements even when GatePro is later disabled, making it a robust enhancement for MoE effectiveness in real-world settings.
Abstract
Modern large language models leverage Mixture-of-Experts (MoE) architectures for efficient scaling, but face a critical challenge: functionally similar experts are often selected simultaneously, creating redundant computation and limiting effective model capacity. Existing auxiliary balance loss methods improve token distribution but fail to address the underlying expert diversity problem. We introduce GatePro, a novel parameter-free method that directly promotes expert selection diversity. GatePro identifies the most similar expert pairs and introduces localized competition mechanisms, preventing redundant expert co-activation while maintaining natural expert specialization. Our comprehensive evaluation demonstrates GatePro's effectiveness across model scales and benchmarks. Analysis demonstrates GatePro's ability to achieve enhanced expert diversity, where experts develop more distinct and complementary capabilities, avoiding functional redundancy. This approach can be deployed hot-swappable during any training phase without additional learnable parameters, offering a practical solution for improving MoE effectiveness.
