Cluster-Specific Tuning

Intel® MPI Library has more than 100 parameters. The defaults are set for common usage and generally provide good performance for most clusters and most applications. However, if you want to get even higher performance, you can use the mpitune utility. This utility uses the Intel® MPI Benchmarks (IMB) as a benchmark program running tests several times with different parameters and searching for the best ones. Start the mpitune utility with the following command:

$ mpitune

Then, start your application with the -tune option to enable the tuned settings:

$ mpirun -tune -perhost 8 –n 64 ./your_app

For best results, run mpitune with write access permissions for <installdir>/<arch>/etc which is the location for tuned parameters. If you do not have write access, a new configuration file will be saved in your current directory.

By default, mpitune uses Intel® MPI Benchmarks as the benchmark program. Alternatively, you can substitute with your benchmark of choice by using the following command:

$ mpitune -test \”your_benchmark –param1 –param2\”

You can then apply the new settings as described in this topic.

The Intel® MPI Benchmarks executable files, which are more optimized for Intel microprocessors than for non-Intel microprocessors, are used by default. This may result in different tuning settings on Intel microprocessors than on non-Intel microprocessors.