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arXiv 2602.02848cs.LG
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零和SVD:平衡损失敏感性以实现低秩LLM压缩

Zero Sum SVD: Balancing Loss Sensitivity for Low Rank LLM Compression

Department of Computer Science, Vanderbilt University, TN, USA(计算机科学系,范德比尔特大学)

Ali Abbasi, Chayne Thrash, Haoran Qin, Shansita Sharma, Sepehr Seifi, Soheil Kolouri

AI总结:

零和SVD通过全局奇异成分选择和零和规则实现低秩LLM压缩,无需优化即可自动生成异质秩,提升压缩效率与性能。

摘要:

大语言模型的进步在许多任务上实现了强劲的性能,但其内存和计算成本仍然阻碍了部署。基于SVD的压缩可以减少存储并通过低秩因子加速推理,但性能取决于在全局压缩比下如何分配秩。先前的方法通常使用相同的秩来处理同样大小的矩阵,尽管损失敏感性存在显著差异,或者依赖于昂贵的迭代预截断优化来确定每个矩阵的秩。我们提出了零和SVD(ZS-SVD),一种后训练方法,通过激活白化和第一阶校准损失估计在白化坐标中进行全局奇异成分选择。ZS-SVD使用零和规则对整个模型进行剪枝,保持累积预测损失变化接近零,从而自动产生异质秩,而无需解决秩分配优化问题。受证据表明梯度接近预训练解决方案时表现出低秩结构的启发,我们还引入了一个可选的轻量级修正,即在截断后应用一次投影梯度更新,然后进行重新截断。在多种LLM架构上的广泛实验显示,在多样化的基准和压缩比下均实现了稳定的提升。代码可在https://github.com/mint-vu/Zero-Sum-SVD获取。

英文摘要:

Advances in large language models have driven strong performance across many tasks, but their memory and compute costs still hinder deployment. SVD-based compression reduces storage and can speed up inference via low-rank factors, yet performance depends on how rank is allocated under a global compression ratio. Prior methods often use homogeneous ranks for similarly sized matrices, despite large differences in loss sensitivity, or rely on expensive iterative pre-truncation optimization to determine per matrix ranks. We propose Zero Sum SVD (ZS-SVD), a post-training method that performs global singular component selection using activation whitening and first-order calibration loss estimates in whitened coordinates. ZS-SVD prunes components across the whole model with a zero sum rule that keeps the cumulative predicted loss change near zero, automatically yielding heterogeneous ranks without solving a rank allocation optimization. Motivated by evidence that gradients near pretrained solutions exhibit low rank structure, we also introduce an optional lightweight correction that applies a single projected gradient update after truncation, followed by re-truncation. Extensive experiments across multiple LLM architectures show consistent gains across diverse benchmarks and compression ratios. Code is available at https://github.com/mint-vu/Zero-Sum-SVD

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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