RE: IB fabrics

From: Bennion, Brian (
Date: Fri Jan 06 2012 - 12:39:04 CST

The only concern that I have seen is the implementation of charm++ on the two IB layers when using IBVERBS instead of the mpi versions.

at our institution we have qlogic and mellanox ib hardware. qlogic in our implementation will only run ibverbs in a software mode and it doesn't do it very well even then.


From: [] On Behalf Of Axel Kohlmeyer []
Sent: Friday, January 06, 2012 9:58 AM
To: Thomas Bishop
Subject: Re: namd-l: IB fabrics

On Fri, Jan 6, 2012 at 12:42 PM, Thomas Bishop <> wrote:
> Is namd very sensitive to which vendor is used for a 40Gbps IB fabric.
> Specifically I'm interested in Qlogic vs. Mellanox.

don't think so, why should it be?

i can think of at least 10 other things that
i would worry about more before worrying
about ib vendor impact on NAMD speed.

. and the things w.r.t. IB vendors that i *would*
worry about are independent of the application.


> Any comments greatly appreciated.
> Thanks
> TOm
> --
> *******************************
> Thomas C. Bishop
> Tel: 318-257-5209
> Fax: 318-257-3823
> ********************************

Dr. Axel Kohlmeyer
College of Science and Technology
Temple University, Philadelphia PA, USA.

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