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From: Jeff Squyres \(jsquyres\) (jsquyres_at_[hidden])
Date: 2006-06-29 13:10:39

> -----Original Message-----
> From: devel-bounces_at_[hidden]
> [mailto:devel-bounces_at_[hidden]] On Behalf Of Patrick Geoffray
> Sent: Wednesday, June 28, 2006 1:23 PM
> To: Open MPI Developers
> Subject: Re: [OMPI devel] Best bw/lat performance for
> microbenchmark/debug utility
> Josh Aune wrote:
> > I am writing up some interconnect/network debugging software that is
> > centered around ompi. What is the best set of functions to
> use to get
> > the best bandwidth and latency numbers for openmpi and why?
> I've been
> You mean MPI functions or internal ompi functions ? For MPI
> functions,
> it depends of what you are looking for. Send/recv is fine but it does
> not show the overlap capability. You would need to do
> something smarter
> with Isend/Irecv/Wait for that (Sandia has a nice bench that
> they should
> release soon). You may also want to measure the penalty for
> unexpected
> messages, the host CPU overhead and the ability to progress.

Patrick's answer is much better than mine. :-)

I was assuming that you would be testing latency/bandwidth, but Patrick
is correct in stating that there are many more things to test than just
those two metrics.

Jeff Squyres
Server Virtualization Business Unit
Cisco Systems