A first example

This tutorial will guide you through the steps of your first SeisSol simulation. We will use the SCEC TPV33 benchmark as an example in this tutorial. We assume that you have successfully compiled SeisSol.

Setup

  • Download the parameter file and additional setup files and put them in your launch directory, hereafter named launch_SeisSol.

  • Download the mesh binary file and the associated xml file and store them in launch_SeisSol. Optional: For performance reasons, we suggest that you store the mesh file in a scratch file system (if one is available at your cluster) and create symbolic links in your launch directory (e.g. ln -s <path/to/tpv33_gmsh> launch_SeisSol/tpv33_gmsh;). You may not see a huge difference in this small test case but for larger meshes, this is the recommended strategy.

  • Create the output directory: mkdir launch_SeisSol/output. For the output files it might also be beneficial to store them in a scratch file system. In this case, create the output directory in your scratch file system and a symbolic link launch_SeisSol/output to this directory.

Execution

To execute SeisSol, change to the launch_SeisSol directory and run: OMP_NUM_THREADS=<threads> mpiexec  -np <n> ./SeisSol_<configuration> parameters.par, where:

  • <configuration> depends on your compilation setting (e.g. SeisSol_Release_dhsw_4_elastic for a Haswell architecture and order 4 accuracy in space and time).

  • <n> is the number of MPI ranks / the number of compute nodes used.

  • <threads> is the number of OpenMP threads per MPI rank, typically the number of CPUS. (If you compiled SeisSol with -DCOMMTHREAD=ON use the number of CPUs - 1, to reserve one CPU for communication).

Hint: Depending on the system you are using, the MPI launcher might be different from mpiexec (e.g. mpiexec.hydra, mpirun, srun). For more infos about how to get optimal performance, have a look at the Optimal environment variables on SuperMUC-NG.

Result verification

SeisSol produces various output files:

The xdmf files can be visualized with Paraview. For the dat files, you can use viewrec.

The outputs of your simulation can be compared with our outputs (using SeisSol) and the outputs of other codes by checking out the uploaded files for this SCEC benchmark on the SCEC Code Verification Project website.