[Beowulf] 64 bit Xeons?

[Mikhail Kuzminsky]

In message from Dale Harris <rodmur at maybe.org> (Tue, 11 Jan 2005 
16:02:39 -0800):
>
>http://www.intel.com/products/server/processors/server/xeon/
>
>So anyone tried the Intel Xeon Processor MP?  Is it just a repackaged
>Itanium?
   MP in Xeon MP means "multiprocessor", i.e. processors which
may work in SMP configurations having more than 2-way (what is
marked as DP for Itanium). 

   Xeon MP (because of sharing of system bus by processors) may have
conflicts at access to main memory. To decrease of this problems 
Xeon MP is equipped w/additional cache memory having high capacity.
But as usually this can't help in the case your applications are
"RAM throughput" -limited and their working set of pages can't
fit in the cache hierarchy. It may be often in HPC area.

   Of course, Xeon MP are much more expensive (than usual Xeon's),
and are relative popular in servers for business applications,
but not in HPC clusters which usually are based on 2-processor 
SMP nodes.

   What is about 64-bit Xeon's - they have codename Nocona and they 
are
compatible w/x86 but not w/Itanium IA-64.

Yours
Mikhail Kuzminsky
Zelinsky Institute of Organic Chemistry
Moscow

  


>
>-- 
>Dale Harris   
>rodmur at maybe.org
>/.-)
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