HP XC System Software Release Notes for Version 3.1

9 Programming and User Environment
This chapter contains information that applies to the programming and user environment.
9.1 Required HP-MPI Option on Systems With a Mix of InfiniBand PCI-X
and PCI Express
To run MPI jobs on a set of nodes that have a mix of PCI-X and PCI Express InfiniBand boards,
you must include the following option with the HP-MPI mpirun command:
-e MPI_IB_MTU=1024
9.1 Required HP-MPI Option on Systems With a Mix of InfiniBand PCI-X and PCI Express 65