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Re: [bgl-discuss] MPI pingpong on BGL

Thanks Bill, 

As I look at the basic pingpong plot under p2p performance it indicates
an asymptotic BW of around 800-880 Mbps. I assume this is node-to-node.
Also I think, the torus channels are 1.4 Gbps each way per node. I would
have thought a larger fraction of the BW would be observed. Thoughts?
 
Perhaps I missed something.

--jeff








On Thu, 2006-01-05 at 15:00, William Gropp wrote:
> At 01:56 PM 1/5/2006, Jeffrey L. Tilson wrote:
> >What kind of node-ASIC to node-ASIC MPI comunications are people seeing
> >using MPI, e.g., Send/Recv pairs in an MPI pingpong code? ( or Pallas :)
> 
> Here are some graphs from shortly after we received the machine:
> 
> http://www-unix.mcs.anl.gov/~gropp/projects/parallel/BGL/mpptest/perf.htm
> 
> These use mpptest (http://www-unix.mcs.anl.gov/mpi/mpptest/) .  We have 
> some other results, including halo exchange; see 
> http://www-unix.mcs.anl.gov/~gropp/projects/parallel/BGL/perf.htm .
> 
> Bill
> 
> >--jeff
> >
> >
> >--
> >__________________________
> >Jeffrey L. Tilson, Ph.D.
> >Renaissance Computing Institute (RENCI)
> >University of North Carolina at Chapel Hill
> >Duke University
> >North Carolina State University
> >
> >Mail to:
> >University of North Carolina at Chapel Hill
> >CB 7583, Carr Building
> >Chapel Hill, NC 27599-7583
> >
> >+1-919-843-7586
> >+1-919-843-7624 (fax)
> >________________________________________
> >
> >- --------------------------------------------------------------------
> >To add or remove yourself from this mailing list, use the 'notifyme'
> >command on any BGL machine. To remove: notifyme -n, to add: notifyme -y.
> 
> William Gropp
> http://www.mcs.anl.gov/~gropp
-- 
__________________________
Jeffrey L. Tilson, Ph.D.
Renaissance Computing Institute (RENCI)
University of North Carolina at Chapel Hill
Duke University
North Carolina State University

Mail to:
University of North Carolina at Chapel Hill
CB 7583, Carr Building
Chapel Hill, NC 27599-7583

+1-919-843-7586
+1-919-843-7624 (fax)
________________________________________

- --------------------------------------------------------------------
To add or remove yourself from this mailing list, use the 'notifyme'
command on any BGL machine. To remove: notifyme -n, to add: notifyme -y.