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Subject: Re: [OMPI devel] trac #2034 : single rail openib btl shows better bandwidth than dual rail (12k< x < 128k)
From: George Bosilca (bosilca_at_[hidden])
Date: 2009-10-06 10:52:45


Don,

This seems a very IB centric problem (and solution) going up in the
PML. Moreover, I noticed that independent on the BTL we have some
problems with the multi-rail performance. As an example on a cluster
with 3 GB cards we get the same performance is I enable 2 or 3. Didn't
had time to look into the details, but this might be a more general
problem.

   george.

On Oct 6, 2009, at 09:51 , Don Kerr wrote:

>
> I intend to make the change suggested in this ticket to the trunk.
> The change does not impact single rail, tested with openib btl, case
> and does improve dual rail case. Since it does involve performance
> and I am adding a OB1 mca parameter just wanted to check if anyone
> was interested or had an issue with it before I committed the change.
>
> -DON
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