Communication-aware scalability analysis based on critical path

With the scale of parallel computing system growing up, the influence of the communication overhead cannot be ignored. Parallel speedup is the most commonly used metric for evaluating scalability in parallel computing, and we propose communication-aware speedup based on the traditional speedup to quantitatively analyze the system scalability. This paper presents the definition of communication-aware scalability, discusses the communication-aware scalability by using critical path, and then quantitatively classifies the systems according to their communication-aware scalabilities. Through case studies, we analyze the communication-aware scalabilities of some parallel systems. A significant conclusion of this paper is that the system is scalable, if the communication overhead increases at a rate with lower exponent than parallel workload.