Sustained Petascale Performance of Seismic Simulations with SeisSol on SuperMUC

Seismic simulations in realistic 3D Earth models require petaor 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-/densematrix 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 (10 grid cells, 5 · 10 degrees of freedom, 5 seconds simulated time), we achieved a sustained performance of 1.09 PFLOPS.