RECAP: Training-Free Compensation for Coarse Activation Channel Pruning in Compressed LLMs

Published: 21 May 2025, Last Modified: 17 Jun 2025MLArchSys 2025 OralEveryoneRevisionsBibTeXCC BY 4.0
Presentation: In-Person
Keywords: Sparsity, Error Compensation, LLM, Efficient AI, Channel Pruning
Presenter Full Name: Mingyu Lee
TL;DR: RECAP is a training-free method that recovers up to 34% accuracy in channel-pruned LLMs by reusing pruning statistics for lightweight error compensation, enabling hardware-friendly compression without sacrificing model quality.
Presenter Email: mlee864@gatech.edu
Abstract: Sparsity is a key enabler for efficient inference in large language models (LLMs). While a wide spectrum of sparsification techniques—from unstructured to highly structured—have been explored to reduce computational overhead, they often involve trade-offs between hardware efficiency and model accuracy. Channel sparsity, in particular, is appealing due to its hardware-friendly structure compared to alternatives like structured N:M sparsity, but suffers from notable accuracy degradation, especially when applied to activations. To bridge this gap, we propose RECAP, a lightweight, training-free compensation method that mitigates the impact of channel pruning induced errors. RECAP exploits the statistics of the pruned channel as a representation of the sparsity-induced error and transfers it to the corresponding weights to compensate for the removal of the channel. Extensive experiments across diverse LLM families and benchmarks demonstrate that RECAP outperforms existing alternatives at all sparsity levels. On LLaMA3-8B, RECAP achieves approximately a 34\% improvement in 0-shot BoolQ benchmark accuracy at a target sparsity ratio of 70\%.
Presenter Bio: Mingyu Lee is an undergraduate researcher at the Synergy Lab, Georgia Institute of Technology, advised by Prof. Tushar Krishna. His research focuses on accelerating AI applications through hardware/software co-design for efficient and practical real-world deployment.
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YouTube Link: https://youtu.be/7xnN1NuxD7Q
YouTube Link Poster: https://youtu.be/cdB1QR_CbxM
Google Slides: https://docs.google.com/presentation/d/1iNCQBLedMH5OKLX9gA8nPRx3iDFZOhTbyKrlZR11G9E/edit?usp=sharing
Poster: Yes
Workshop Registration: Yes, the presenter has registered for the workshop.
YouTube Link Short: TBA
Submission Number: 3
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