IntelMPI is now the only MPI type supported for Windows and Linux platforms. The Intel MPI files are included in the fluent installation folder, inside the Ansys package. On typical systems, no setup is required.
2022 R2: Intel MPI 2021 is used by default on Linux platforms, both by Fluent and FENSAP-ICE. Intel MPI 2018 is still the default on Windows platforms.
The MPI version can be toggled for both FENSAP-ICE and Fluent by setting an environment variable to 2018 or 2021, for example : export FLUENT_INTEL_MPI_VERSION=2018.
The MPI type used can be changed globally by modifying fensapice/config/mpi.txt.
The MPI type can also be changed in the user account by adding the file ~/.ansys/fensapice/mpi.txt under %appdata%/Ansys/fensapice/mpi.txt on Windows.
Important: On Linux clusters with multiple compute nodes, Intel MPI 2021 requires an
up-to-date UCX driver library. For computations that experience stability issues on
multiple compute nodes, enable the MPI_FI_PROVIDER:Linux=verbs line in
fensapice/config/mpi.txt, or use the environment variable
FI_PROVIDER=verbs when launching sub parallel jobs. Switching to
Intel MPI 2018 is also an option on supported platforms.
For advanced options, refer to the official Intel documentation, https://software.intel.com/en-us/articles/intel-mpi-library-documentation.
Windows:
The default mpiexec option will be set to
–localonly. Any change to the mpi arguments in the
FENSAP-ICE Run panel will override this option and use the
specified options instead.
Linux:
To run on a list of remote hosts, such as on a cluster, a
machinefile must be set up in the mpi argument list. On a
queuing system, it might be required to configure it with the following option:
-machinefile $NODEFILE, where
NODEFILE contains the list of CPU cores.