Differences in the Performance of Parallel Applications in Physical and Virtual Clusters

This article evaluates how software environment influences on the performance of parallel applications when they run in a dedicated, shared or virtual cluster, to identify the factors that influence performance according to the type of environment and the behavior of the applications. The evaluations were performed using the NAS benchmark software and the clusters were built on the same hardware configurations. The data obtained served to identify the factors involved in the variations of execution times between the different tested configurations. The results indicate that the performance of some applications is not always better in a physical cluster than in a virtual cluster, which a priori seems counterintuitive.