Battle Of The Supercomputers

In a computing power struggle tinged with national pride, IBM Corp. says it hopes to regain the title for world's fastest supercomputer from Japan's NEC Corp. in 2004 when Big Blue delivers a machine that will model nuclear weapons for the U.S. government.

"There's a bit of nationalism involved," said Jack Dongarra of the University of Tennessee. "We like to think in the U.S. that we have the most powerful computers. Well, the Japanese have it now."

Japan's NEC jolted the computer world in April when its Earth Simulator, which knits together 5,000 processors to attain a theoretical speed of 40 trillion calculations per second, became the first machine built outside the United States to top the supercomputer speed list.

The Yokohama, Japan-based Earth Simulator not only took the lead, but did so by trouncing the then-fastest machine, IBM's ASCI White, by running almost five times as fast.

"It's an exciting time," said Dongarra, who leads the group of researchers that tracks the world's 500 speediest computers, known as the Top500 list. "We went through a period of doldrums. The Earth Simulator has revived interest in high-power computing."

At the SuperComputing 2002 conference in Baltimore on Tuesday, U.S. Energy Secretary Spencer Abraham was to announce a $290 million contract with IBM to build two new supercomputers, one of which, dubbed ASCI Purple, is expected to clock in at 100 teraflops, or trillions of calculations per second.

Like so many of America's fastest computers, ASCI Purple will be used to simulate the explosions and decay of the U.S. nuclear weapons stockpile without resorting to test detonations of the warheads.

In 2005, IBM plans to deliver a second supercomputer to the Department of Energy, dubbed Blue Gene/Lite, which will run 130,000 processors at a theoretical top speed of 360 teraflops — more than triple the speed of ASCI Purple.

IBM says Blue Gene/Lite, running the Linux operating system, will tackle research on global climate change and study the interaction between atmospheric chemistry and pollution.

The "Lite" designation refers to IBM's ongoing Blue Gene supercomputer experiment, where the company has been researching the techniques behind building a supercomputer that could handle a petaflop — or a quadrillion calculations — per second.

Both of the mega-machines will reside at the DOE's Lawrence Livermore National Laboratory in Livermore, California.

Significantly for IBM, the operating software and the interconnection of ASCI Purple's 12,500 processors are the same basic innards that power its P-Series mainframe computers, said Dave Turek, IBM's vice president of deep computing. Except that ASCI Purple will harbor two petabytes — or quadrillion bytes — of disk storage, about 30 times the contents of the Library of Congress, Turek estimated.

The tough part, Turek and Dongarra say, is interconnecting the processors so they act like a single human brain, rather than a collection of cells. IBM said ASCI Purple would approach the brain's processing power.

"When they get this large it becomes a significant challenge to put these things together," Dongarra said. "It's a real tour de force in engineering."

All but a few of today's top supercomputers use a parallel processing system that interconnects thousands of mass-produced microprocessors.

The biggest exception is NEC's Earth Simulator, which uses a "vector parallel" construction of linked processors, an older method that handles computations one at a time.

Whether IBM's ASCI Purple becomes the first machine to knock NEC's Earth Simulator off the block remains to be seen.

Other companies are working toward the same goal, including Hewlett-Packard Co. — builder of the current No. 2 and 3 machines — Cray Inc., which is designing a pair of alternate systems for the Department of Energy, and NEC itself, analysts said.

About 90 percent of the top 500 supercomputers are U.S.-made, according to the Top 500 list, compiled by researchers at University of Mannheim, Germany; the Department of Energy's National Energy Research Scientific Computing Center in Berkeley, California. and the University of Tennessee.

For Turek, nationalism is no concern.

"We're international," he said. "For us, every nation is an IBM nation."