Performance of large scale MHD simulation of global planetary magnetosphere with massively parallel scalar type supercomputer including post processing

To use the massively parallel scalar type supercomputer for the large scale numerical magnetospheric simulation, the computational performance of magneto-hydro-dynamic (MHD) code is evaluated. We have made performance tuning of a three-dimensional MHD code for space plasma simulations on the HA8000 with 1024 cores at the University of Tokyo. For parallelization of the MHD code, we use four different methods, i.e., regular one-dimensional, two-dimensional, three-dimensional domain decomposition methods and a cache-hit type of three-dimensional domain decomposition method. We found that the regular two and three-dimensional decompositions are suitable for HA8000 system. In addition we found the three problems to run the large scale simulation, data I/O, storage system and post processing. To improve them, we can simulate the high resolution Saturn's magnetosphere.