Saved in:
Bibliographic Details
Main Authors: Tian, Jiayi, Solgi, Ryan, Lu, Jinming, Yang, Yifan, Li, Hai, Zhang, Zheng
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2505.23966
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911425209827328
author Tian, Jiayi
Solgi, Ryan
Lu, Jinming
Yang, Yifan
Li, Hai
Zhang, Zheng
author_facet Tian, Jiayi
Solgi, Ryan
Lu, Jinming
Yang, Yifan
Li, Hai
Zhang, Zheng
contents Large Language Models (LLMs) have enabled remarkable progress in natural language processing, yet their high computational and memory demands pose challenges for deployment in resource-constrained environments. Although recent low-rank decomposition methods offer a promising path for structural compression, they often suffer from accuracy degradation, expensive calibration procedures, and result in inefficient model architectures that hinder real-world inference speedups. In this paper, we propose FLAT-LLM, a fast and accurate, training-free structural compression method based on fine-grained low-rank transformations in the activation space. Specifically, we reduce the hidden dimension by transforming the weights using truncated eigenvectors computed via head-wise Principal Component Analysis, and employ a greedy budget redistribution strategy to adaptively allocate ranks across decoders. FLAT-LLM achieves efficient and effective weight compression without recovery fine-tuning, which could complete the calibration within a few minutes. Evaluated across 5 models and 11 datasets, FLAT-LLM outperforms structural pruning baselines in generalization and downstream performance, while delivering inference speedups over decomposition-based methods.
format Preprint
id arxiv_https___arxiv_org_abs_2505_23966
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle FLAT-LLM: Fine-grained Low-rank Activation Space Transformation for Large Language Model Compression
Tian, Jiayi
Solgi, Ryan
Lu, Jinming
Yang, Yifan
Li, Hai
Zhang, Zheng
Computation and Language
Large Language Models (LLMs) have enabled remarkable progress in natural language processing, yet their high computational and memory demands pose challenges for deployment in resource-constrained environments. Although recent low-rank decomposition methods offer a promising path for structural compression, they often suffer from accuracy degradation, expensive calibration procedures, and result in inefficient model architectures that hinder real-world inference speedups. In this paper, we propose FLAT-LLM, a fast and accurate, training-free structural compression method based on fine-grained low-rank transformations in the activation space. Specifically, we reduce the hidden dimension by transforming the weights using truncated eigenvectors computed via head-wise Principal Component Analysis, and employ a greedy budget redistribution strategy to adaptively allocate ranks across decoders. FLAT-LLM achieves efficient and effective weight compression without recovery fine-tuning, which could complete the calibration within a few minutes. Evaluated across 5 models and 11 datasets, FLAT-LLM outperforms structural pruning baselines in generalization and downstream performance, while delivering inference speedups over decomposition-based methods.
title FLAT-LLM: Fine-grained Low-rank Activation Space Transformation for Large Language Model Compression
topic Computation and Language
url https://arxiv.org/abs/2505.23966