[Beowulf] scalability of cluster paper

[Robert G. Brown]

On Thu, 17 Feb 2005, Paul Johnson wrote:

> I am wondering if anyone could point me to a paper on the scalability 
> issues of NOWs clusters or
> Beowulf clusters using MPI.  Im curious what kind of scalability people 
> see for clusters less than 10 nodes. 
> Any reference to a paper would be greatly appreciated.  I've been doing 
> alot of scholar.googling but
> havent found what Im looking for yet.

There is a whole chapter on Amdahl's Law and scaling in my online
beowulf book (and several online talks and white papers ditto).  Look on

  http://www.phy.duke.edu/brahma

or

  http://www.phy.duke.edu/~rgb

under the Beowulf link.

Scalability isn't a question of number of nodes per se, it is a question
of the parallel speedup you observe as a FUNCTION of the number of nodes
participating in the problem, the problem "size" (really all other
parameters, not just size), the network characteristics, and the system
CPU/memory/bus characteristics.  The presentation I give is a simplified
one that lets you see the general idea, but the reality is much more
complex for some classes of problem.

HTH,

   rgb

-- 
Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb at phy.duke.edu