Exploring the Performance Impact of Virtualization on an HPC Cloud

The feasibility of the cloud computing paradigm is examined from the High Performance Computing (HPC) viewpoint. The impact of virtualization is evaluated on our latest private cloud, the AIST Super Green Cloud, which provides elastic virtual clusters interconnected by Infini Band. Performance is measured by using typical HPC benchmark programs, both on physical and virtual cluster computing clusters. The results of the micro benchmarks indicate that the virtual clusters suffer from the scalability issue on almost all MPI collective functions. The relative performance gradually becomes worse as the number of nodes increases. On the other hand, the benchmarks based on actual applications, including LINPACK, OpenMX, and Graph 500, show that the virtualization overhead is about 5% even when the number of nodes increase to 128. This observation leads to our optimistic conclusions on the feasibility of the HPC Cloud.