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arXiv 2602.02400cs.LG
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对噪声数据和LLM预训练损失发散的实证研究

An Empirical Study on Noisy Data and LLM Pretraining Loss Divergence

University of Oxford(牛津大学);FAIR at Meta(Meta 的 FAIR)

Qizhen Zhang, Ankush Garg, Jakob Foerster, Niladri Chatterji, Kshitiz Malik, Mike Lewis

AI总结:

本研究通过实证分析揭示噪声数据如何导致LLM预训练中的损失发散,并区分噪声与高学习率引起的发散模式。

摘要:

大规模预训练数据集推动了大型语言模型(LLMs)的成功。然而,这些网络级语料库不可避免地包含大量噪声数据,这是由于未受监管的网络内容或数据中固有的随机性。尽管LLM预训练器经常推测此类噪声会加剧大规模LLM预训练的不稳定性,甚至在最坏情况下导致损失发散,但这一现象仍缺乏深入理解。在本研究中,我们系统地实证研究了噪声数据是否导致LLM预训练发散以及其机制。通过在原本干净的数据集中注入受控的合成均匀随机噪声,我们分析了从4.8亿到52亿参数规模的模型的训练动态。我们证明噪声数据确实会引起训练损失发散,并且发散的概率强烈依赖于噪声类型、噪声量和模型规模。我们进一步发现,由噪声引起的发散表现出与高学习率引起的发散不同的激活模式,并提供了区分这两种失败模式的诊断方法。这些结果为大规模、受控地刻画噪声数据如何影响LLM预训练中的损失发散提供了全面的特征描述。

英文摘要:

Large-scale pretraining datasets drive the success of large language models (LLMs). However, these web-scale corpora inevitably contain large amounts of noisy data due to unregulated web content or randomness inherent in data. Although LLM pretrainers often speculate that such noise contributes to instabilities in large-scale LLM pretraining and, in the worst cases, loss divergence, this phenomenon remains poorly understood.In this work, we present a systematic empirical study of whether noisy data causes LLM pretraining divergences and how it does so. By injecting controlled synthetic uniformly random noise into otherwise clean datasets, we analyze training dynamics across model sizes ranging from 480M to 5.2B parameters. We show that noisy data indeed induces training loss divergence, and that the probability of divergence depends strongly on the noise type, amount of noise, and model scale. We further find that noise-induced divergences exhibit activation patterns distinct from those caused by high learning rates, and we provide diagnostics that differentiate these two failure modes. Together, these results provide a large-scale, controlled characterization of how noisy data affects loss divergence in LLM pretraining.

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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