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Subject: Re: [OMPI users] Heterogeneous OpenFabrics hardware
From: Peter Kjellstrom (cap_at_[hidden])
Date: 2009-01-27 10:19:02

On Tuesday 27 January 2009, Jeff Squyres wrote:
> It is worth clarifying a point in this discussion that I neglected to
> mention in my initial post: although Open MPI may not work *by
> default* with heterogeneous HCAs/RNICs, it is quite possible/likely
> that if you manually configure Open MPI to use the same verbs/hardware
> settings across all your HCAs/RNICs (assuming that you use a set of
> values that is compatible with all your hardware) that MPI jobs
> spanning multiple different kinds of HCAs or RNICs will work fine.
> See this post on the devel list for a few more details:

So is it correct that each rank will check its HCA-model and then pick up
suitable settings for that HCA?

If so maybe OpenMPI could fall back to a very conservative settings if more
than one HCA model was detected among the ranks. Or would this require
communication in a stage where that would be complicated and/or ugly?