[Beowulf] Re: vectors vs. loops

[Philippe Blaise]

Douglas Eadline - ClusterWorld Magazine wrote:

>On Tue, 3 May 2005, Philippe Blaise wrote:
>
>  
>
>>Robert G. Brown wrote:
>>
>>    
>>
>>>....
>>>
>>>Still, the marketplace speaks for itself.  It doesn't argue, and isn't
>>>legendary, it just is.
>>>....
>>>      
>>>
>>But, does the hpc marketplace have a direction ?
>>    
>>
>
>Just as any market place it is ruled by price/performance. One could argue 
>that during the "vector machine" epoch there was an artificial market that 
>was due to the cold war. Performance at any price was an important 
>strategic issue.
>
>  
>
You really think, that even today, the market place is ruled by price / 
performance ratio ?
So why don't we use millions of slow and cheap cpus ?
With this kind of argument we must stop the research programs, and try 
to transform all the
scientific codes for embarrisingly parallel computing !

More seriously, the market place seems mostly governed by big US 
companies and
financial directors.
Moreover, remember that some years ago NEC and Fujitsu supercomputers 
have been
taxed by the US government. (and that was not during the cold war !).
See for example
http://www.freetrade.org/pubs/articles/cd-supercomputer.html

Today everyone should be happy to see that some companies like Cray
are trying to do better than HP or IBM in the linux cluster area, event 
it if it's not
the Cray of yesterday as you said.
I think that this is partially due to the "NEC earth simulator effect", 
and that linux clusters
performances and functionalities are not fantastic for parallel jobs 
compare to a good old T3E.

The price/perf ratio is too simplistic.
The marketplace at a given instant means nothing.


Phil.