Performance Evaluation of Magnetohydrodynamics Simulation for Magnetosphere on K Computer

Abstract

To use the massively parallel scalar type supercomputer for the large scale numerical magnetospheric simulation, we made performance evaluation of a three-dimensional Magnetohydrodynamic (MHD) simulation code for space plasma simulations of planetary magnetosphere on the K computer with 262,144 cores at RIKEN. 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 one-dimensional decomposition and cache-hit type of three-dimensional decomposition achieves the best performance and our MHD code can scale over 200,000 processes on the K computer.