Space Science Simulation at UNH Now Better, Faster, Cheaper
By David Sims, Institute for the Study of Earth, Oceans, and Space
June 25, 2008
Left to right, Kai Germaschewski, Andrew Foulks, Joachim "Jimmy" Raeder, and Doug Larson next to the cluster of PlayStation3 consoles used for simulate the interaction between Earth's magnetic field and the solar wind. Credit: Kristi Donahu
Cashing in on the underlying technology that seamlessly renders graphics for
state-of-the-art video games, space scientists at UNH have bundled together
40 PlayStation3 consoles to affordably simulate one of the “grand challenges” of
modern computational science – the interaction between Earth’s
magnetic field or “magnetosphere” and the solar wind. Climate change
is another supercomputing grand challenge.
“You need a lot of computing power to do video games realistically,
to run the graphics, and there are lots of projects in which people have used
PlayStations to do scientific calculations,” says space physicist and
magnetospheric modeler Joachim “Jimmy” Raeder of the Institute
for the Study of Earth, Oceans, and Space (EOS).
Indeed, as was recently announced, the new $133 million “Roadrunner” supercomputer
at the Los Alamos National Laboratory will use the same technology created
to power video games to solve classified military problems.
The heart of the supercomputing power, and of PlayStation3’s gee-whiz
graphics, is a chip called the Cell Broadband Engine, which can perform up
to two-hundred-billion operations per second. The superchip was co-developed
by Sony, IBM, and Toshiba.
Until now, Raeder’s simulation group at EOS’s Space Science Center
(SSC) has been running its vastly complex Open Geospace General Circulation
Model – a “magnetohydrodynamic” simulation of the interaction
between Earth’s magnetosphere and the solar wind – on an 8,000-pound,
$750,000 collection of 320 processors. They will now be able to achieve the
same computing speed with the 40 PlayStations at $400 a piece.
However, in order to be able to run the simulation on the game consoles, the
PlayStation hardware needed significant “tweaking” to accommodate
an open-source operating system. Moreover, it required Raeder’s SSC colleague
Kai Germaschewski nearly two month’s of effort to reprogram the simulation
program itself before it could run on the new superchip.
The 40-PlayStation supercomputer can theoretically perform up to 8 trillion
operations per second. However, Raeder notes, a mere one trillion per second
is a more realistic number since no program can fully exploit the computer
Of course, even that kind of mind-boggling speed is far short of the one thousand
trillion operations per second (what’s termed a “teraflop”)
that the Los Alamos machine recently achieved by using what would be the equivalent
of 20,000 PS3 consoles cobbled together.
But UNH’s relatively modest effort will get Raeder’s group ready
for the first civilian teraflop machine the National Science Foundation (NSF)
will make available to civilian researchers by 2011.
“When that machine comes online we will be ready to take full advantage
of it,” says Raeder.
Raeder’s project is being funded by a four-year, $1.5 million NSF grant
recently won by his simulation group at SSC. Work on the PS3 project also involved
Doug Larson, Daniel Bergeron, and Andrew Foulks of the UNH computer science
The simulation work done by the SSC group is connected with a NASA mission
on which Raeder is a co-investigator.
The Time History of Events and Macroscale Interactions during Substorms or
THEMIS mission hopes to resolve one of the oldest mysteries in space physics – what
physical process in near-Earth space initiates the violent eruptions of the
aurora that occur during a period of one hour or less. This period, known as
a substorm, is when energy is rapidly released in the magnetospheric tail and
creates the brilliant northern (and southern) lights.
The two-year mission consists of five identical probes that will study the
violent, colorful eruptions of auroras. The simulation work done at UNH will
help scientists better understand and interpret the data they’re getting
from the THEMIS spacecraft.