arXiv AI

Experts Exhibit Structured Redundancy: Structure-Preserving Expert Pruning for Mixture-of-Experts Large Language Models

The paper introduces a structure‑preserving approach to prune experts in Mixture‑of‑Experts large language models, addressing memory overhead while maintaining performance. It observes that expert outputs exhibit structured redundancy, with stable rank and entropy effective rank far below the nominal number of experts. Two pruning methods—Projection Energy Expert Pruning (PEEP) and Distributional Coverage Expert Pruning (DCEP)—use router‑derived weights to preserve global structural relationships and local importance, achieving superior results on DeepSeek‑V2‑Lite and Qwen3‑30B‑A3B at 75% and 50% expert retention.

Hugging Face Trending Papers
Jul 2

Generic Expert Coverage for Pruning SparseMixture-of-Experts Language Models

Sparsely activated Mixture-of-Experts (MoE) language models contain substantial structured redundancy among routed experts, but pruning them without downstream calibration data remains challenging. Existing expert-pruning methods typically rely on a single aggregated importance score, which can bias the retained set toward experts favored by dominant calibration patterns.

arXiv AI
Sep 17

Higher-order pruning of experts in mixture-of-experts language models

The paper introduces HOPE, a second‑order pruning method for Mixture‑of‑Experts language models that accounts for cooperative interactions between experts. Unlike first‑order methods such as REAP, HOPE derives an objective that provably bounds pruning error and is shown to outperform baselines across three large MoE models, multiple calibration sets, and diverse benchmarks, especially at high pruning rates and on agentic tasks. The results demonstrate that preserving expert interactions allows aggressive compression with minimal performance loss on complex workloads.

By Alex M. Tseng, Prannay Kaul, Luca Zancato, Wei Xia, Stefano Soatto
arXiv Machine Learning
Sep 30

OMP-MoE: Efficient Expert Pruning for Mixture-of-Experts LLMs via Orthogonal Matching Pursuit

OMP-MoE is a training‑free compression framework that prunes redundant experts in Mixture‑of‑Experts large language models by framing the problem as sparse signal reconstruction solved with Orthogonal Matching Pursuit. The method greedily selects expert contributions as dictionary atoms to minimize reconstruction error, then optimizes cross‑layer expert allocation via a water‑filling strategy, and finally introduces an adaptive inference mechanism (OMP‑MoE†) that dynamically adjusts expert activation based on energy prediction. Experiments on Qwen, DeepSeek‑V2, GPT‑OSS, and Mixtral MoE show consistent performance gains at 25‑50% pruning ratios, with Qwen3‑30B‑A3B retaining 93.3% of original performance at 50% compression while achieving significant speedups.

By Dezhi Li, Lujun Li, Qiyuan Zhu, Hao Gu, Bei Liu, Sirui Han, Yike Guo
arXiv Machine Learning
Oct 3

Redundancy Meets Synergy: Dependency-aware Expert Selection for MoE via Submodular Optimization

The paper introduces DS-MoE, a framework that selects a compact subset of experts in Mixture-of-Experts models using difference-of-submodular (DS) optimization. It analyzes the loss degradation via a second-order Taylor expansion to uncover redundancy and synergy among experts, and formulates the selection objective to decouple these effects. A majorization-minimization algorithm with monotonicity guarantees efficiently identifies the optimal subset, and experiments show DS-MoE outperforms state‑of‑the‑art baselines.

By Zheng Lin, Shaoke Fang, Yuxin Zhang, Jinfeng Xu, Zihan Fang, Zhe Chen, Wei Ni, Jun Luo, Symeon Chatzinotas