After building one of the world’s fastest supercomputers on its first try, Apple Computer Inc. is again teaming with Virginia Tech to make another high-performance machine using its new 64-bit Xserve G5 computer.

Xserve, a thinner, more compact machine designed for clustering with other computers, will replace the supercomputer Virginia Tech built in November using off-the-shelf G5 PowerMacs.

Project leader Srinidhi Varadarajan said the university will upgrade from PowerMacs to Xserves in April or May. Virginia Tech is still negotiating the price with Apple, though Varadarajan said any additional cost to the school would be “fairly minimal.”

The school’s cluster of 1,100 G5s surprised the supercomputing world last year by performing 10.3 trillion operations per second, making it the third-fastest machine in the world. Varadarajan and his staff of student volunteers built it in just weeks for $7 million, a fraction of the cost of traditional supercomputers.

In comparison, the world’s fastest machine, Earth Simulator Center in Japan, cost at least $250 million and can run 35.9 trillion operations per second. The next fastest is a $215 million Hewlett-Packard computer at Los Alamos National Laboratory that can complete 13.9 trillion operations per second.

Xserves use the same IBM PowerPC 970 microprocessors and Mac OS X operating system, and the upgraded supercomputer will use the same high-speed Infiniband network as the G5. What makes them better for supercomputing is that they were meant to be part of a network, while the G5 was always built for personal computing, said Phil Schiller, Apple’s senior vice president of Worldwide Product Marketing.

“Xserves have information displays in the front that tell you what’s happening with processors, what’s happening with network connections at a glance, while a desktop doesn’t do any of that,” Schiller said.

And at 1.75 inches thick, the Xserves are built for stacking. They’ll effectively shrink Virginia Tech’s supercomputer to one-third its current size. The specialized components also will produce less heat, work more efficiently, and ultimately make a faster machine, Varadarajan said, though he doesn’t know how fast.

Jack Dongarra, a computer science professor at the University of Tennessee who compiles an annual list of the top 500 supercomputers, said the announcement suggests that Apple is ready to enter the market of high-end computers, an area where the company has had only a minimal presence.

“I think they did surprise a lot of people with their original machine,” Dongarra said. “My guess is they’re testing the water to see if the [education] community is interested in the kind of machine that Virginia Tech has.”

Since it was completed in November, Virginia Tech’s G5 supercomputer hasn’t been used for any of the scientific experiments that university officials were expecting. The upgrade will stall any practical use in academic research for another four or five months, but Varadarajan said it will be worth the wait.

“This will look a lot more like a traditional supercomputer,” he said. “It will allow us to address a different set of problems, larger problems over a longer period of time.”

School officials said they’re not certain what will happen to the G5 PowerMacs after they’re replaced.


Virginia Tech

Apple Computer Inc.