Analytic Models of Applications in Multi-core Computers

Multi-core computers are becoming increasingly ubiquitous. Understanding and being able to predict the performance of applications that run on such machines is paramount. This paper first shows experimentally that memory contention resulting from multiple cores accessing shared memory can become a significant component of an application´s execution time. Then, the paper develops an approximate single-class analytic performance model that captures the effect of memory contention. The model is validated through measurements taken on a micro-benchmark and on well known Unix memory benchmark programs on machines with 4, 12, and 16 cores. The paper also shows that there is a significant difference in the predictions when memory contention is not considered.