# Programming Environment

## Compilers

The Lawrence HPC programming environment has the choice of two compilers: Intel and Gnu 4.8.5 (gcc).

## OpenMP

Two options in Lawrence are available for OpenMP: OpenMP Intel and Gnu.

To choose a version of OpenMP, add the version number and "/intel" or "/gcc" to the module command.

```
# For the OpenMPI module with Gnu:
[user.name@usd.local@login ~]$ module load openmpi-1.6/gcc

############## or ################

#For the OpenMPI module with OpenMP Intel:
[user.name@usd.local@login ~]$ module load openmpi-1.6/intel

```

## MPI

MPI's available with Lawrence: open MPI, mpich (ethernet), and mvapich (infinaband), intel impi

| **MPI Platform** | Module Name      | Module Name        |
| ---------------- | ---------------- | ------------------ |
| Open MPI         | openmpi-1.6/gcc  | openmpi-1.6/intel  |
|                  | openmpi-1.8/gcc  | openmpi-1.8/intel  |
|                  | openmpi-2.0/gcc  | openmpi-2.0/intel  |
| mpich            | mpich/gcc        | mpich/intel        |
| mvapich          | mvapich2-2.2/gcc | mvapich2-2.2/intel |

```
[user.name@usd.local@login ~]$ module avail
------------------------------------------- /usr/share/Modules/modulefiles --------------------------------------------
dot         module-git  module-info modules     null        use.own

-------------------------------------------------- /act/modulefiles ---------------------------------------------------
cuda-9.1           intel              mvapich2-2.2/gcc   openmpi-1.6/intel  openmpi-2.0/gcc
gaussian/16        mpich/gcc          mvapich2-2.2/intel openmpi-1.8/gcc    openmpi-2.0/intel
impi               mpich/intel        openmpi-1.6/gcc    openmpi-1.8/intel

```

#### To load/unload an MPI module:

```
############## Load ################
[user.name@usd.local@login ~]$ module load openmpi-2.0/gcc

############# Unload ###############
[user.name@usd.local@login ~]$ module unload openmpi-2.0/gcc
```

#### To view the version of MPI in use:

```
[user.name@usd.local@login ~]$ mpirun --version
[user.name@usd.local@login ~]$ mpirun --version
mpirun (Open MPI) 2.0.1

Report bugs to http://www.open-mpi.org/community/help/
```


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