HP-MPI User's Guide (11th Edition)

Understanding HP-MPI
Running applications on Windows
Chapter 3 95
Figure 3-1 Job Allocation
To run an MPI application, submit the mpirun command to the
scheduler. HP-MPI uses the environment of the task and job where
mpirun is executing to launch the required mpids that start the ranks.
It is important that mpirun uses only a single processor for its task
within the job so the resources can be used by the other processes within
the MPI application. (This is the opposite of MSMPI, which requires all
of the processor to be allocated to the mpiexec task by the MPI
application.)
Running HP-MPI on Windows 2003/XP
To run HP-MPI on Windows 2003/XP systems use appfile mode or the
-hostlist/-hostfile flags.