Seismic simulations in realistic 3D Earth models require peta- or even exascale computing power to capture small-scale features of high relevance for scientific and industrial applications. In this paper, we present optimizations of SeisSol --- a seismic wave propagation solver based on the Arbitrary high-order accurate DERivative Discontinuous Galerkin ADER-DG method on fully adaptive, unstructured tetrahedral meshes --- to run simulations under production conditions at petascale performance. Improvements cover the entire simulation chain: from an enhanced ADER time integration via highly scalable routines for mesh input up to hardware-aware optimization of the innermost sparse-/dense-matrix kernels. Strong and weak scaling studies on the SuperMUC machine demonstrated up to 90% parallel efficiency and 45% floating point peak efficiency on 147k cores. For a simulation under production conditions 108 grid cells, 5i¾?1010 degrees of freedom, 5 seconds simulated time, we achieved a sustained performance of 1.09i¾?PFLOPS.
['Alexander Breuer', 'Alexander Heinecke', 'Sebastian Rettenberger', 'Michael Bader', 'Alice-Agnes Gabriel', 'Christian Pelties']
Sustained Petascale Performance of Seismic Simulations with SeisSol on SuperMUC