gem5-SysXelerator: A Full-System Simulator for Accelerator Architectures

The growing computation demand for artificial intelligence applications has fueled the implementation of applicationspecific accelerators in modern compute systems. The bottleneck of these systems is shifting from raw compute capacity to data movement on the full system. However, today’s accelerator simulation tools focus heavily on the hardware implementation of accelerators and neglect the system perspective. This paper proposes gem5SysXelerator, an extension to the widely used gem 5 simulator. It includes an accelerator model which abstracts the detailed hardware implementation but retains detailed communication, as well as a flexible task workload model that covers all aspects from small micro-benchmarks to full neural networks. The extension enables the exploration of new research directions by implementing clusters, a custom cache hierarchy, and a non-coherent interconnect between the accelerators. gem5-SysXelerator, when validated with the Gemmini accelerator platform, demonstrates a deviation as low as $0.5 \%$ from the Gemmini system.