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Subject: Re: [OMPI users] Pros and cons of --enable-heterogeneous
From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2010-10-08 14:19:39

On Oct 7, 2010, at 3:44 PM, David Ronis wrote:

> I have various boxes that run openmpi and I can't seem to use all of
> them at once because they have different CPU's (e.g., pentiums, athlons
> (both 32 bit) vs Intel I7 (64 bit)).

You could also just compile everything 32 bit, and then not use the heterogeneous flag.

> I'm about the build 1.4.3 and was
> wondering if I should add --enable-heterogenous to the configure flags.

Keep in mind that you may still lose precision if you, for example, send a 64 MPI_DOUBLE to a machine where MPI_DOUBLE is 32 bit. There's not too much that OMPI can do there.

The heterogeneous flag is more traditionally used for endian flipping kinds of things.

Jeff Squyres
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