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Los Alamos, NM -- The supercomputers of the future will
never crash and will cost far less to run than today's
machines. At least that's the vision of a scientist at the
National Nuclear Security Administration's Los Alamos
National Laboratory.
"Everyone's fixed on the mantra of performance at all
costs," said Wu Feng of Los Alamos' Advanced Computing
Laboratory. "What we've done is redefine the
price-to-performance ratio to look at efficiency,
reliability and availability, in other words, total cost of
ownership."
Feng and colleagues Michael Warren and Eric Weigle
developed the first of this new breed of high-performing,
low-cost computers, which they named "Green Destiny." The
machine has been operating with unprecedented stability and
performance efficiency for more than eight months in a
dusty warehouse where temperatures routinely reach
85-degrees Fahrenheit.
Feng, Warren and Weigle argue that the costs of
computing should include electrical power, infrastructure,
air conditioning, floor space, time lost to system failures
and salaries for the people needed to keep finicky machines
operating. Supercomputers of the future may very well be
similar to Green Destiny, they say: small, extremely stable
and miserly in their power use.
Green Destiny represents a new "flavor" of
supercomputer, Feng said. The machine packs 240 Transmeta
processors that operate at 667 MegaHertz, mounted onto a
half-inch-slim compact motherboard, or blade. A total of 24
blades then mount into a RLX Technologies System 324
chassis, and then ten chassis, with network switches, are
mounted in a standard computer rack.
Currently computing at a peak rate of 160-billion
operations per second, Green Destiny uses less than ten
percent of the electricity and twenty-five percent of the
space to give performance comparable to the previous
generation of so- called cluster computers. More important
is reliability, Feng said.
"As the push for performance goes up, so does the power
consumption. And system failure is directly proportional to
power consumption," he pointed out. "If your machine isn't
available all the time, then you can't do any
computing.
In fact, unpublished empirical data from computer
vendors indicate that as processor temperatures increase by
10-degrees Celsius, failure rates double. Typical
computing-intensive businesses depend on hundreds or even
thousands of identical servers to handle multiple requests
for information simultaneously. When the servers go down,
hourly losses can range up to $6.5 million for a large
brokerage firm.
Green Destiny, whose processors operate roughly
one-tenth as hot as market- leading chips, has been running
continuously since September without air filtration or
special cooling. In fact, it kept humming even with the
fans removed.
"It's absolutely rock solid," Feng said. "It's so
reliable we only keep one spare blade around, and we have
never needed it."
In a recent paper, available at http://public.lanl.gov/feng/Bladed-Beowulf.pdf
online, Feng predicts, based on Moore's law, that the drive
for increased performance will result in "the
microprocessor of 2010 having over one billion transistors
and dissipating over one kilowatt of thermal energy; this
is considerably more energy per square centimeter than even
a nuclear reactor."
Beowulf clusters, developed at NASA in the early 1990s,
group commodity processors with commercial switches and
have attracted much attention because they're able to
handle many computations simultaneously. A larger version
of the Green Destiny Bladed Beowulf cluster would require
far less space than a traditional Beowulf cluster. Putting
2,000 of the bladed machines together could yield an
enormous savings in space, and in costs, with floor space
in Silicon Valley renting for more than $150 a square
foot.
Feng argued that with all these factors taken into
account, the true price-to- performance rating for Green
Destiny would be at least twice as good as other
supercomputers.
Internet pioneer Gordon Bell, software guru Linus
Torvalds and other guests visited Los Alamos Laboratory
recently to learn more about Green Destiny and the
Supercomputing in Small Spaces project, whose web site is
at http://sss.lanl.gov
online.
Stephen Lee, acting deputy leader of Los Alamos'
Computer and Computational Sciences Division, said Green
Destiny represents a promising research advance, but
emphasized the national need for large platforms that are
uniquely able to move huge amounts of data in and out of
memory rapidly, such as Los Alamos' Q machine, developed
for NNSA's Advanced Simulation and Computing program, or
ASCI.
"This could be the next important step in scalable
supercomputing, but the challenge of maintaining the
nation's nuclear stockpile in the face of aging weapons,
eroding expertise and nearly a decade without nuclear
testing demand three-dimensional, full physics computing on
tera-scale computers today, while designers and engineers
with weapon test experience are still available to validate
the ASCI simulations." Lee said.
The best use for machines like Green Destiny might be in
the inexpensive development of scientific codes for a wide
range of applications, Feng and Lee said. Once the code has
been developed and stabilized, it could move to an
ASCI-style supercomputer.
Feng's team at Los Alamos originally bought the machine
from RLX Technologies to host large volumes of data. After
several delays in compiling the data, they decided to make
a cluster instead and tested it with some high- performance
applications, such as Warren's simulation of the beginnings
of the universe and his three-dimensional model of
supernovae. Among planned future jobs for Green Destiny are
global climate modeling, large-scale molecular dynamics,
computational fluid dynamics and bioinformatics.
"At first, we did not think that there was anything
particularly novel about this," Feng said. "We showed it to
fellow researchers at a supercomputing conference last
November, and we saw more than 7,000 hits on our web site
the following week. This project has taken on a life of its
own."
The Transmeta Crusoe processor provides about 75 percent
of the performance of similarly clocked chips from a major
manufacturer used in other Beowulf clusters. So Green
Destiny might be compared to the tortoise, eventual winner
of the fabled race with the speedy hare.
"If you want to solve a problem that you can complete on
a traditional supercomputer faster than the mean time
between failures, I guarantee we'll run slower than a
traditional supercomputer or virtually any other cluster,"
Feng said. "But if you're running something that takes
weeks or months, eventually the stable machine will win the
race."
The Los Alamos Computer Science Institute supported the
research and development of Green Destiny. The Institute is
funded by NNSA's ASCI program.
Los Alamos National Laboratory is operated by the
University of California for the National Nuclear Security
Administration of the Department of Energy and works in
partnership with NNSA's Sandia and Lawrence Livermore
national laboratories to support NNSA in its mission.
Los Alamos enhances global security by ensuring the
safety and reliability of the U.S. nuclear weapons
stockpile, developing technical solutions to reduce the
threat of weapons of mass destruction and solving problems
related to energy, environment, infrastructure, health and
national security concerns.
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