BENCHMARK ANALYSIS AND APPLICATION RESULTS FOR LATTICE BOLTZMANN SIMULATIONS ON NEC SX VECTOR AND INTEL NEHALEM SYSTEMS

Abstract

Classic vector systems have all but vanished from recent TOP500 lists. Looking at the recently introduced NEC SX-9 series, we benchmark its memory subsystem using the low level vector triad and employ the kernel of an advanced lattice Boltzmann flow solver to demonstrate that classic vectors still combine excellent performance with a well-established optimization approach. To investigate the multi-node performance, the flow field in a real porous medium is simulated using the hybrid MPI/OpenMP parallel ILBDC lattice Boltzmann application code. Results for a commodity Intel Nehalem-based cluster are provided for comparison. Clusters can keep up with the vector systems, however, require massive parallelism and thus much more effort to provide a good domain decomposition.