A Data Prefetcher-Based 1000-Core RISC-V Processor for Efficient Processing of Graph Neural Networks

Abstract

Graphs-based neural networks have seen tremendous adoption to perform complex predictive analytics on massive real-world graphs. The trend in hardware acceleration has identified significant challenges with harnessing graph locality and workload imbalance due to ultra-sparse and irregular matrix computations at a massively parallel scale. State-of-the-art hardware accelerators utilize massive multithreading and asynchronous execution in GPUs to achieve parallel performance at high power consumption. This paper aims to bridge the power-performance gap using the energy efficiency-centric RISC-V ecosystem. A 1000-core RISC-V processor is proposed to unlock massive parallelism in the graphs-based matrix operators to achieve a low-latency data access paradigm in hardware to achieve robust power-performance scaling. Each core implements a single-threaded pipeline with a novel graph-aware data prefetcher at the 1000 cores scale to deliver an average 20× performance per watt advantage over state-of-the-art NVIDIA GPU.