[MPICH] mpirun vs. mpiexec

[Anthony Chan]

On Tue, 5 Jun 2007, Matthew Chambers wrote:

>
> > > I was contemplating switching over to the setup where each user starts
> > > their own ring. I have an older cluster that I am planning on testing
> > > this setup with. I am curious to know if there are
> > > advantages/disadvantages over the two setups. Would I notice anything
> > > different in terms of performance?
> >
> > I don't think you will see any difference in MPI performance whether mpds
> > are started by root or users...
>
> If one is using a lot nodes, doesn't setting up the MPI ring incur quite a
> bit of overhead with the ssh calls?
>

I am refering to the MPI communication performance, not the startup cost
of setting up the mpd ring.  Besides setting 38 nodes of mpds with ssh
is fast.  Of course, if you are talking about thousand of nodes, Pete
Wyckoff's mpiexec is probably the best option as pbs_mom is already
running on each compute node....

A.Chan