Parallel Computing is Everywhere

The paper deals with the OpenMP parallel implementation of a high-order Discontinuous Galerkin solver for computational fluid dynamics (CFD) and computational aeroacoustics (CAA) applications. The use of the shared memory view of the OpenMP paradigm is here explored through three different parallel implementation strategies. The numerical experiments on 2D and 3D test cases, which consider the effects of different platforms, compilers and space discretizations, indicate that all the code versions perform quite satisfactory. In particular, the OpenMP domain decomposition algorithm reaches the highest level of parallel efficiency at low computational loads, while a colouring approach excels for the largest simulations. The performance gain observed in using a hybrid MPI/OpenMP version of the DG code on large HPC facilities will be demonstrated.