Replies to post #46999 on Advanced Micro Devices Inc (AMD)

[chipguy]

Itanic2 does well on specfp because the spec routines fit in the on-chip cache.

Not that one would expect someone who calls a chip by
a perjorative to have a clue but you are quite wrong.

http://www.spec.org/cpu2000/analysis/memory/


Most real numeric tasks are not in-cache and those specfp results don't pan out in the real world.

That isn't at all what NASA has found with its original
512P Altix. They liked it so much in fact they expanded
their Altix facility by a factor of 20 times.

http://www.sgi.com/features/2004/oct/columbia/

"On NASA's previous supercomputers, simulations showing five years worth of changes in ocean temperatures and sea levels were taking 12 months to model. But on the SGI® Altix® system, scientists could simulate decades of ocean circulation in just days, while producing simulations in greater detail than ever before. And the time required to assess flight characteristics of an aircraft design, which involves thousands of complex calculations, dropped from years to a single day. "That kind of leap is incredible," says Taft. "What took a year on the best computing technology previously available, we could now accomplish in days on the Altix system."

I also like this little shot at IBM/Bluegene.

"We needed a system designed to efficiently execute the
algorithms used in NASA's premier science codes, rather
than one that would merely do well on artificial benchmarks."