Abstract This paper presents porting of a discontinuous Galerkin shallow water equation model (DG-SWEM version 3.0.2), a discontinuous Galerkin solver for hurricane storm surge, to NVIDIA graphics processing units (GPUs). Time-explicit discontinuous Galerkin methods contain a large number of degrees of freedom but have been shown to exhibit a large amount of data parallelism due to the loose coupling between elements and thus are naturally mapped to the central processing unit (CPU) architecture. A previous framework in porting DG-SWEM to GPUs required converting subroutines from Fortran to C + + to be used with CUDA C + + . By using OpenACC and unified memory, we simplified the porting process and maintained a single codebase for both CPU and GPU versions. We tested the code using a large Hurricane Harvey scenario on NVIDIA’s Grace Hopper chip and compared the GPU code’s performance on multiple H200 nodes to the CPU code on Grace and AMD Milan CPU nodes.
Wichitrnithed et al. (Tue,) studied this question.