Both versions have been compiled with Intel compiler 2018 update 2. On GPU-nodes they have been compiled with GPU-support. On Infiniband nodes (i.e. all cluster nodes) they have been compiled with Infiniband support.
2.1.3
OpenMPI version 2.1.3 is the latest version in the 2-series. This is a bug fix release.
Use (linux): module load openmpi/Intel/2.1.3
3.0.0
OpenMPI version 3.0.0 is the initial release of the new 3-series and introduces several new features.
See the release notes.
Use (linux): module load openmpi/Intel/3.0.0
Older releases
In addition to these, we still maintain version 1.6.3, 1.10.7 and 2.1.1.
1.10.7 is the final release in the 1-series.
1.6.3 and 2.1.1 will be removed from the system in the future.
If you are unsure, you should use version 3.0.0
OpenMPI documentation can be found here.