Performance of a high-order finite difference compressible flow solver in Fortran on next-generation heterogeneous computing architectures

Next-generation high-performance computing architecture will create new challenges in the use of current computational fluid dynamics codes. Code must be adapted to new systems while maintaining capability on existing systems. The efforts made to prepare a Fortran-based high-order finite difference hydrodynamic code for the upcoming HPC systems are discussed. Focus is placed on those specific to Fortran implementations, including OpenMP support, loop/memory structure requirements, and interoperability-based strategies. Porting strategies on upcoming vs. current systems and methods used to minimize code versioning for different systems are presented. A scaling study on current and upcoming systems applying the immersed boundary method to a supersonic flow is conducted. Achieved scaling and throughput are presented and remaining bottlenecks in performance are discussed.