提出几何感知的低比特量化方法,提升大模型在资源受限设备上的性能。
RSAVQ: Riemannian Sensitivity-Aware Vector Quantization for Large Language Models
- 基于黎曼几何设计误差引导机制,抑制量化误差传播。
- 2比特量化下,比现有方法低0.4困惑度,零样本准确率提升1.5。
- 适合部署大模型到移动端或边缘设备的研究者使用。
大语言模型(LLMs)在自然语言处理任务中表现卓越,但参数量指数增长给资源受限设备的部署带来挑战。向量量化(VQ)在极低比特(如2-4比特)量化方面前景广阔,但现有方法存在方向误差无约束和比特分配不佳的问题。本文提出RSAVQ,一种新的VQ框架,通过两个几何驱动创新解决上述问题:(1) 误差方向敏感引导(EDSG),利用费舍尔信息矩阵(FIM)诱导的黎曼度量,将量化误差投影至参数空间中低敏感方向,沿负自然梯度方向进行投影以有效抑制误差扩展;(2) 权重通道敏感度引导(WCSG),通过FIM曲率分析构建通道级敏感度度量,动态指导比特资源分配,在指定比特约束下实现全局最优量化。实验表明,RSAVQ优于现有方法。例如,在LLaMA-3 8B的2比特量化中,相比VPTQ和QuIP#,困惑度(PPL)降低0.4,零样本准确率提升1.5。该工作为受限环境提供了实用解决方案,并建立了信息几何与神经网络量化之间的理论桥梁,推动高效深度学习发展。
原文摘要 · Abstract (English)
Large language models (LLMs) have demonstrated remarkable performance across a wide range of natural language processing tasks. However, their exponentially increasing parameters pose significant challenges for deployment on resource-constrained devices. Vector Quantization (VQ) shows great promise for low-bit quantization (e.g., 2 to 4 bits), but existing work faces two key challenges: unconstrained direction error and suboptimal bit allocation. In this paper, we propose RSAVQ, a novel VQ framework to enhance extremely low-bit quantization for LLMs. RSAVQ introduces two geometry-driven innovations that effectively mitigate above limitations: (1) Error Direction Sensitivity Guidance (EDSG), which leverages the Fisher Information Matrix (FIM)-induced Riemannian metric to project quantization errors onto low-sensitivity directions in the parameter space. Specifically, this projection is performed along the negative natural gradient direction, which effectively suppresses error expansion. (2) Weight Channel Sensitivity Guidance (WCSG) , which constructs a channel-wise sensitivity metric via FIM curvature analysis to dynamically guide bit resource allocation. The approach facilitates a globally optimal quantization solution within prescribed bit constraints. Experiments demonstrate that RSAVQ outperforms existing methods for LLMs. For example, in 2-bit quantization of LLaMA-3 8B, RSAVQ leads baselines like VPTQ and QuIP# by 0.4 in perplexity (PPL) and 1.5 in zero-shot accuracy. This work offers a practical solution for constrained environments and a theoretical bridge between information geometry and the quantization of neural networks, advancing efficient deep learning.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。