Abstract—This paper analyzes energy characteristics of parallel algorithms executed on scalable multicore processors. Specifically, we provide a methodology for evaluating energy scalability of parallel algorithms while satisfying performance requirements. Four parallel algorithms are analyzed to illustrate our method. We study the sensitivity of our analysis to changes in parameters such as the ratio of power required for computation versus power required for communication. The results suggest that power and performance scalability of a parallel algorithm can be quite different. Our method can be used to determine how many cores to use in order to minimize energy consumption.