[Beowulf] Network benchmark - MPI

[Jonathan Michael Nowacki]

Tony,

I'm actually out at the MBL for a summer internship and I just got word
that they have experienced the 4 node thing as well.  Thought you should
know.

More detailed info on our clusters @
http://jbpc.mbl.edu/computing/hardware.html

The nodes only have 512MB memory and are going through about 2 gigs of
swap, but we are upgrading them.  My boss says MrBayes is probably limited
by the default 4 Markov chains, and thats why their is no significant
gains after 4 nodes.  I wonder if quad processor nodes would speed it up,
or if the actually speed of each processor is the only thing that would
matter.

   Jon

On Fri, 2 Jul 2004, Tony Travis wrote:

> Jonathan Michael Nowacki wrote:
> 
> > Just wondering, if their is a benchmark or program that I can use to test
> > the maximum bandwidth of a cluster from node to node, or all nodes
> > communicating to the master node.  I'm thinking any kind of bandwidth test
> > will do, but the purpose is to see how much traffic a 40 node cluster can
> > take when running MrBayes (a MPI program).
> 
> Hello, Jon.
> 
> I can't help with the benchmark, but I'm also looking at the performance 
> of MrBayes on a 32-node 100Base-T openMosix cluster. I've found that it 
> runs 'best' on four nodes. I've tried 1, 2, 4, 8, 16 nodes and 250000 
> generations. I'd be interested to hear about other people's experience 
> of running MrBayes on multiple processors?
> 
> 	Tony.
> -- 
> Dr. A.J.Travis,                     |  mailto:ajt at rri.sari.ac.uk
> Rowett Research Institute,          |    http://www.rri.sari.ac.uk/~ajt
> Greenburn Road, Bucksburn,          |   phone:+44 (0)1224 712751
> Aberdeen AB21 9SB, Scotland, UK.    |     fax:+44 (0)1224 716687
> 
> 
>