[Beowulf] Intel Quad-Core or AMD Opteron

[richard.walsh at comcast.net]

-------------- Original message -------------- 
From: Greg Lindahl <lindahl at pbm.com> 

> On Thu, Aug 23, 2007 at 09:09:57AM -0400, Douglas Eadline wrote: 
> 
> > Naturally, if you have four processes running 
> > it is best if each one gets its own woodcrest. To the OS 
> > the all look the same. Other than Intel MPI, I don't 
> > know of any other MPI that attempts to optimize this. 
> 
> InfiniPath MPI has always optimized this. Of course, there's no way it 
> can read your mind and know if you are going to run a second 4-core 
> job on the same node, so there is no perfect default. But it has 
> switches to give you either behavior, tightly packed or spread out. 

An additional example is Liquid Computing's implementation of MPI
for their 4x2 way mother boards.  You have complete control of 
placement (not withstanding Greg's mind reading point).

rbw
-- 

"Making predictions is hard, especially about the future." 

Niels Bohr 

-- 

Richard Walsh 
Thrashing River Consulting-- 
5605 Alameda St. 
Shoreview, MN 55126 

Phone #: 612-382-4620
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