VQKV: High-Fidelity and High-Ratio Cache Compression via Vector-Quantization

Fuente: arXiv
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Main Authors: Wang, Yixuan, Shi, Qingyu, Zhou, Jiayu, Liu, Dianbo, He, Ziwei, Lin, Zhouhan
Format: Preprint
Published: 2026
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author Wang, Yixuan
Shi, Qingyu
Zhou, Jiayu
Liu, Dianbo
He, Ziwei
Lin, Zhouhan
author_facet Wang, Yixuan
Shi, Qingyu
Zhou, Jiayu
Liu, Dianbo
He, Ziwei
Lin, Zhouhan
contents The growing context length of Large Language Models (LLMs) enlarges the Key-Value (KV) cache, limiting deployment in resource-limited environments. Prior training-free approaches for KV cache compression typically rely on low-rank approximation or scalar quantization, which fail to simultaneously achieve high compression ratios and high reconstruction fidelity. We propose VQKV, a novel, training-free method introducing vector quantization (VQ) to obtain highly compressed KV representations while preserving high model fidelity, allowing for the representation of thousands of floating-point values with just a few integer indices. As a result, VQKV achieves an 82.8\% compression ratio on LLaMA3.1-8B while retaining 98.6\% of the baseline performance on LongBench and enabling 4.3x longer generation length on the same memory footprint.
format Preprint
id arxiv_https___arxiv_org_abs_2603_16435
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle VQKV: High-Fidelity and High-Ratio Cache Compression via Vector-Quantization
Wang, Yixuan
Shi, Qingyu
Zhou, Jiayu
Liu, Dianbo
He, Ziwei
Lin, Zhouhan
Computation and Language
The growing context length of Large Language Models (LLMs) enlarges the Key-Value (KV) cache, limiting deployment in resource-limited environments. Prior training-free approaches for KV cache compression typically rely on low-rank approximation or scalar quantization, which fail to simultaneously achieve high compression ratios and high reconstruction fidelity. We propose VQKV, a novel, training-free method introducing vector quantization (VQ) to obtain highly compressed KV representations while preserving high model fidelity, allowing for the representation of thousands of floating-point values with just a few integer indices. As a result, VQKV achieves an 82.8\% compression ratio on LLaMA3.1-8B while retaining 98.6\% of the baseline performance on LongBench and enabling 4.3x longer generation length on the same memory footprint.
title VQKV: High-Fidelity and High-Ratio Cache Compression via Vector-Quantization
topic Computation and Language
url https://arxiv.org/abs/2603.16435