Large-Scale 3-D Fluid Simulations for Implosion Hydrodynamics on the Earth Simulator

A three-dimensional fluid code, IMPACT-3D has been parallelized with high performance Fortran (HPF) on the Earth Simulator. IMPACT-3D is an implosion analysis code using TVD scheme, which performs three-dimensional compressible and inviscid Eulerian fluid computation with the explicit 5-point stencil scheme for spatial differentiation and the fractional time step for time integration. The third dimension of an array was distributed for the parallelization, but the first dimension was preserved for the vector processing. Shift communications were manually tuned to get best performance by using HPF/JA extensions, which was designed to give the users more control over sophisticated parallelization and communication optimizations. Even the Earth Simulator Center claims more than 95% of vectorization ratio and more than 50% of parallelization efficiency to run the simulation code on the Earth Simulator, we have cleared these severe criteria for using 128 nodes of the Earth Simulator. We are very encouraged to get this outstanding performance on a real-world scientific application parallelized with HPF