# 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 with the options parallelization=hybrid and generatedKernels=yes (see Compiling SeisSol).

## Setup¶

• Follow steps 1. - 3. from the [[configuration documentation|configuration]].
• 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_master.par, where:

• <configuration> depends on your compilation setting (e.g. SeisSol_release_generatedKernels_dsnb_hybrid_none_9_4 for a Sandy Bridge architecture and order 4 accuracy in space and time).
• <n> is the number of processes/ the number of partitions used.
• <threads> is the number of OpenMP threads per process (we usually use the number of CPU per core).

Hint: Depending on the system you are using, the MPI launcher might be different from mpiexec (e.g. mpiexec.hydra).

## Result verification¶

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.