# Enable Intel MPI
<a name="intelmpi-v3"></a>

Intel MPI is available on the AWS ParallelCluster AMIs.

**Note**  
To use Intel MPI, you must acknowledge and accept the terms of the [Intel simplified software license](https://software.intel.com/en-us/license/intel-simplified-software-license).

By default, Open MPI is placed on the path. To enable Intel MPI instead of Open MPI, you must first load the Intel MPI module. Then, you need to install the latest version by using `module load intelmpi`. The exact name of the module changes with every update. To see which modules are available, run `module avail`. The output is as follows.

```
$ module avail
-----------------------------/usr/share/Modules/modulefiles --------------------------------
dot                            modules        
libfabric-aws/1.16.0~amzn3.0   null
module-git                     openmpi/4.1.4
module-info                    use.own

-----------------------------/opt/intel/mpi/2021.6.0/modulefiles ---------------------------
intelmpi
```

To load a module, run `module load modulename`. You can add this to the script used to run `mpirun`.

```
$ module load intelmpi
```

To see which modules are loaded, run `module list`.

```
$ module list
Currently Loaded Modulefiles:
  1) intelmpi
```

To verify that Intel MPI is enabled, run `mpirun --version`.

```
$ mpirun --version
Intel(R) MPI Library for Linux* OS, Version 2021.6 Build 20220227 (id: 28877f3f32)
Copyright 2003-2022, Intel Corporation.
```

After the Intel MPI module has been loaded, multiple paths are changed to use the Intel MPI tools. To run code that was compiled by the Intel MPI tools, load the Intel MPI module first.

**Note**  
Intel MPI isn't compatible with AWS Graviton-based instances.

**Note**  
Before AWS ParallelCluster version 2.5.0, Intel MPI wasn't available on the AWS ParallelCluster AMIs in the China (Beijing) and China (Ningxia) Regions.