ScaleDNN: Data Movement Aware DNN Training on Multi-GPU

Abstract

Training Deep Neural Networks (DNNs) models is a time-consuming process that requires immense amount of data and computation. To this end, GPUs are widely adopted to accelerate the training process. However, the delivered training performance rarely scales with the increase in the number of GPUs. The major reason behind this is the large amount of data movement that prevents the system from providing the GPUs with the required data in a timely fashion. In this paper, we propose ScaleDNN, a framework that systematically and comprehensively investigates and optimizes data-parallel training on two types of multi-GPU systems (PCIe-based and NVLink-based). Specifically, ScaleDNN performs: i) CPU-centric input batch splitting, ii) mini-batch data pre-loading, and iii) model parameter compression to effectively a) reduce the data movement between the CPU and multiple GPUs, and b) hide the data movement overheads by overlapping the data transfer with the GPU computation. Our experimental results show that ScaleDNN achieves up to 39.38%, with an average of 17.96% execution time saving over modern data parallelism on PCIe-based multi-GPU system. The corresponding execution time reduction on NVLink-based multi-GPU system is up to 19.20% with an average of 10.26%.