cheap clusters

[Douglas Eadline]

On Wed, 4 Apr 2001, Velocet wrote:

> On Wed, Apr 04, 2001 at 04:22:50PM -0400, Troy Baer's all...
> > On Wed, 4 Apr 2001, Robert G. Brown wrote:
> > > Speaking of DDR Athlons -- are there any motherboards that are actually
> > > available out there?  Most of what I was able to find in a modest
> > 
> > There are a couple uniproc Athlon/DDR motherboards that are available
> > right now if you look hard.  The most widely available ones are the
> > 
> > The major problem with DDR memory right now is finding DIMMs that are
> > stable at the 133MHz system bus speed.  Some batches of Nanya PC2100-rated
> > DDR RAM are very unstable (i.e. cause silent lockups) unless you downclock
> 
> Im lost here. Why are people buying the most expensive single
> nodes for their computations? Arent we all building/running beowulfs
> because no single machine could deliver the power we need? So why
> get 10 super expensive DDR machines with super expensive DDR ram instead
> of 40 less expensive machines? I dont understand the underlying
> philosophy. Is the idea to get the most money in machinery into the
> smallest space? Whats the criteria here? Is everything 'automatically'
> considered 'cheap' because its not a $10M supercomputer here? (I remember
> reading the word "cheap" in the Beowulf FAQ somewhere, but it doesnt
> seem to be echoed by many people on the list, except a few who mainly
> stay off the list and talk with me privately - for fear of being
> chastized for the most cycles per dollar??)


People doing work on clusters look at price to performance.
If the price of DDR is a price to performance win for your application
then it makes sense to buy it. 

This is the GREAT thing about clusters. You buy what you need to 
get the best performance for yoru problem(s). There is no "best cluster".

Doug
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