论文标题
DeepNet:将变压器扩展到1,000层
DeepNet: Scaling Transformers to 1,000 Layers
论文作者
论文摘要
在本文中,我们提出了一种简单而有效的方法来稳定极深的变压器。具体而言,我们引入了一个新的归一化函数(DeepNorm),以修改变压器中的残差连接,并伴随理论得出的初始化。深入的理论分析表明,模型更新可以稳定地界定。所提出的方法结合了两个世界中最好的方法,即,在LN和稳定训练前的良好表现,使DeepNorm成为首选的选择。我们成功地扩展了最大1,000层(即2,500个关注和前馈网络子层)的变压器,这是比以前的Deep Transformers更深的一个数量级。值得注意的是,在具有7,482个翻译方向的多语言基准上,我们具有3.2b参数的200层模型显着优于48层的最先进的模型,其12B参数乘以5 BLEU点,这表明一个有希望的缩放方向。
In this paper, we propose a simple yet effective method to stabilize extremely deep Transformers. Specifically, we introduce a new normalization function (DeepNorm) to modify the residual connection in Transformer, accompanying with theoretically derived initialization. In-depth theoretical analysis shows that model updates can be bounded in a stable way. The proposed method combines the best of two worlds, i.e., good performance of Post-LN and stable training of Pre-LN, making DeepNorm a preferred alternative. We successfully scale Transformers up to 1,000 layers (i.e., 2,500 attention and feed-forward network sublayers) without difficulty, which is one order of magnitude deeper than previous deep Transformers. Remarkably, on a multilingual benchmark with 7,482 translation directions, our 200-layer model with 3.2B parameters significantly outperforms the 48-layer state-of-the-art model with 12B parameters by 5 BLEU points, which indicates a promising scaling direction.