How Good Are Low-Power 64-Bit SoCs for Server-Class Workloads?

Emerging system-on-a-chip (SoC)-based microservers promise higher energy efficiency by drastically reducing power consumption albeit at the expense of loss in performance. In this paper we thoroughly evaluate the performance and energy efficiency of two 64-bit eight-core ARM and x86 SoCs on a number of parallel scale-out benchmarks and high-performance computing benchmarks. We characterize the workloads on these servers and elaborate the impact of the SoC architecture, memory hierarchy, and system design on the performance and energy efficiency outcomes. We also contrast the results against those of standard x86 servers.