FRED: Flexible REduction-Distribution Interconnect and Communication Implementation for Wafer-Scale Distributed Training of DNN Models

TL;DR

FRED is a flexible wafer-scale interconnect designed for high-performance distributed DNN training, significantly reducing training times across various models by optimizing communication patterns and supporting in-switch collective operations.

Contribution

The paper introduces FRED, a novel wafer-scale interconnect that enhances flexibility and performance for distributed DNN training, enabling efficient execution of diverse parallelization strategies.

Findings

FRED reduces training time for ResNet-152 by 1.76X.

FRED improves Transformer-17B training time by 1.87X.

FRED supports in-switch collective communication, halving network traffic.

Abstract

Distributed Deep Neural Network (DNN) training is a technique to reduce the training overhead by distributing the training tasks into multiple accelerators, according to a parallelization strategy. However, high-performance compute and interconnects are needed for maximum speed-up and linear scaling of the system. Wafer-scale systems are a promising technology that allows for tightly integrating high-end accelerators with high-speed wafer-scale interconnects, making it an attractive platform for distributed training. However, the wafer-scale interconnect should offer high performance and flexibility for various parallelization strategies to enable maximum optimizations for compute and memory usage. In this paper, we propose FRED, a wafer-scale interconnect that is tailored for the high-BW requirements of wafer-scale networks and can efficiently execute communication patterns of different parallelization strategies. Furthermore, FRED supports in-switch collective communication execution that reduces the network traffic by approximately 2X. Our results show that FRED can improve the average end-to-end training time of ResNet-152, Transformer-17B, GPT-3, and Transformer-1T by 1.76X, 1.87X, 1.34X, and 1.4X, respectively when compared to a baseline waferscale 2D-Mesh fabric.