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

Example applications
ping_pong_ring.c (HP-UX and Linux)
Appendix A234
> [1:hostB] ping-pong 0 bytes ...
> 0 bytes: 4.38 usec/msg
> [2:hostC] ping-pong 0 bytes ...
> 0 bytes: 4.42 usec/msg
> [3:hostD] ping-pong 0 bytes ...
> 0 bytes: 4.42 usec/msg
The table showing SHM/VAPI is printed because of the "-prot" option
(print protocol) specified in the mpirun command. In general, it could
show any of the following settings:
VAPI: InfiniBand
UDAPL: InfiniBand
IBV: InfiniBand
PSM: InfiniBand
MX: Myrinet MX
IBAL: InfiniBand (on Windows only)
IT: IT-API on InfiniBand
GM: Myrinet GM2
ELAN: Quadrics Elan4
TCP: TCP/IP
MPID: commd
SHM: Shared Memory (intra host only)
If the table shows TCP/IP for one or more hosts, it is possible that the
host doesn't have the appropriate network drivers installed.
If one or more hosts show considerably worse performance than another,
it can often indicate a bad card or cable.
If the run aborts with some kind of error message, it is possible that
HP-MPI determined incorrectly what interconnect was available. One
common way to encounter this problem is to run a 32-bit application on a
64-bit machine like an Opteron or Intel64. It is not uncommon for the
network vendors for InfiniBand and others to only provide 64-bit
libraries for their network.
HP-MPI makes its decision about what interconnect to use before it even
knows the application's bitness. In order to have proper network
selection in that case, one must specify if the app is 32-bit when running
on Opteron and Intel64 machines: