OpenMPI

An MPI Implementation for Parallel Computing

Homepage Version(s): 4.1.0, 4.1.6, 2.1.0

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OpenMPI requires an environment module

In order to use OpenMPI, you must first load the appropriate environment module:

module load gnu/intel/nvhpc openmpi

OpenMPI is one of several implementations of the Message Passing Interface (MPI) model of parallel computing for distributed systems. OpenMPI is an open-source implementation of this model with a wide range of powerful features.

Using OpenMPI on RCC resources

Notice

OpenMPI 4.1.6 will only work with GNU GCC 8.5.0, and Intel 21 compilers.

There are three different implementations of OpenMPI available on the HPC: Intel, GNU GCC, and NVHPC:

Intel:

# Load default environment module
$ module load intel openmpi

# Load alternative OpenMPI version
$ module load intel openmpi/2.1.0
$ module load intel openmpi/4.1.6

GNU GCC:

# Load default environment module
$ module load gnu openmpi

# Load alternative OpenMPI version
$ module load gnu openmpi/2.1.0
$ module load gnu openmpi/4.1.6

NVHPC:

# Load default environment module
$ module load nvhpc openmpi

Running OpenMPI programs

Regardless of which platform compiler your MPI program executes on, the syntax is the same:

srun -n N program.x # This will run a program with N processors using OpenMPI

This would typically go in a Slurm submit script.