Simulating life’s beginning and accurately predicting hurricane paths are
two distant dreams that came a small step closer to reality when NASA
recently was first to “boot” what may be the most powerful parallel
supercomputer of its kind.

Able to calculate airflow around an aircraft in a day instead of a year,
the “SGI 512-processor Origin 3000” came to life at NASA Ames Research
Center in California’s Silicon Valley. Ames contributed innovations to
previous test bed machines that helped make the 512-processor computer
possible. To many people, the most impressive products of supercomputers
like the Origin are animations that are the envy of Hollywood; but to
scientists these ever-faster, electronic minds have the ability to unlock
nature’s secrets.

“What used to take a year to calculate on a single processor might be done
in less than a day on a 512-processor machine,” said Chris Henze of Ames,
who is working on simulations of protein formation with colleague Andrew
Pohorille.

“Nevertheless,” said Henze, “with current supercomputer power it takes
months or years of calculations to simulate how even a small protein
molecule folds into a certain shape. This is important because a protein’s
shape largely determines what the protein can do, such as make muscles move
or allow the immune system to recognize intruders. In the future, with even
more powerful supercomputers, we hope to be able to design protein
molecules with specific shapes and jobs.”

The 512 will lead to faster and better development of spacecraft, according
to John Ziebarth, deputy chief of the Numerical Aerospace Simulation
Division at NASA Ames. “With large NASA computer codes, we are getting 10
times improvement in performance,” he said.

“In one project underway at Ames, NASA scientists will be able to see
important features in hurricanes,” said Ames computer scientist Bob Ciotti.
“Data from satellites and other observations analyzed on this class of
machines will help us learn how to better predict hurricane behavior, or
better answer important questions about global climate change.”

Though the 512 greatly improves and speeds computations, Ames scientists
continue to advance the supercomputing state-of-the-art with partner SGI,
Mountain View, CA. NASA and SGI have been cooperating under a “memorandum
of agreement” since 1998. “SGI is proud to be partnered with NASA Ames and
their world-class scientists and engineers to help them analyze and solve
America’s most complex problems,” said Anthony Robbins, president, SGI
Federal.

For the last few years Ames computer scientists have encouraged SGI to
connect many computer processor chips in a new way when building the
largest of SGI’s parallel supercomputers. These machines include many
central processing unit (CPU) chips instead of just one or a few CPUs like
older supercomputers. Within the last 5 years, microprocessors have become
much more powerful, and computer makers have found that building a
supercomputer with thousands of processors is cost-effective. But making it
work efficiently has been a problem until now.

The solution, Ziebarth said, was to suggest to SGI that it modify its
computer systems to act as if each had one large memory even though, in
reality, each has a large number of memory units.

“We call this a ‘single system image’ (SSI),” Ziebarth said. Ames also
encouraged SGI to combine pairs of parallel supercomputers into even bigger
single machines. “We said to SGI, if you’ll build a 512-CPU system using
SSI, then we have a technique that will speed up processing about 10
times.” Earlier, NASA Ames programmer Jim Taft invented the technique,
shared memory multi-level parallelism, that greatly simplifies authoring
software for modern parallel-processor supercomputers by enabling easy
communication across many CPUs.

To make the prototype 512 machine, Ames and SGI combined two 256-processor
machines. Commercially available 512 machines, including the Origin 3000
that was booted this month at Ames, resulted from the experience gained in
making the prototype. In a few days, the Army is expected to boot two more
Origin 3000 512-machines, the second and third of their kind.

In the next few months, Ames and SGI will connect two commercial 512
machines to make a test bed 1024 SSI computer. “According to our
projections, the 1024-processor machine could deliver about twice the
performance of the 512,” said Bill Feiereisen, chief of the Ames Numerical
Aerospace Simulation Division.

Stunning images, animation and additional technical information about NASA
Ames’ supercomputer efforts are available on the Internet at these URLs:

http://www.nas.nasa.gov/About/Media/medialibrary.html

http://www.nas.nasa.gov/gridpoints