Effects of Hybrid CPU and Cache Architectures on Parallel HPC and Cloud Applications

Abstract

Hybrid CPU architectures have entered the mainstream desktop computing with the announcement of Intel's Alderlake architecture. Such a transition to heterogeneous CPU architecture has various performance and power implications on existing parallel workloads. In this paper we study the effects and impact of hybrid core and cache architecture on the performance of highly parallel HPC workloads. We also illustrate interesting thread scaling behavior for parallel workloads and describes the reason for such behavior both qualitatively and quantitatively. We also explore the impact of hybrid cache architecture on parallel shared data HPC applications. Finally, we illustrate that 1) parallel applications with work imbalance (i.e., threads in application perform different amount of work) scale better across hybrid cores when thread affinity is disabled and 2) hybrid cache architecture has very little impact on parallel shared data applications except for some workloads with locks. This work lays the foundation for our future work which focuses on extending this work to model parallel workloads and hybrid CPU architectures to improve their performance in terms of execution time, memory usage and power consumption.