PCs Hit the 'Outer Limits'

When you have a big job--like searching the universe for signs of intelligent life--you need all the help you can get. That was the idea behind the May 1999 launch of SETI@home, an imaginative application of distributed computing that could have far-reaching implications--for business.

SETI@home, a project supported by the nonprofit SETI Institute in Mountain View, California, and other groups, has harnessed the Internet--and people's imaginations--to organize almost 2 million volunteer PCs into a virtual massively parallel computer.

The task: analyzing radio signals picked up by the Arecibo radio telescope in Puerto Rico--the one featured in the 1997 movie Contact. The goal: detecting the kind of deep-space radio signals that could indicate communication by other intelligence in the universe. The strategy: to link together as many of the world's computers as possible to accomplish the goal.

"The Internet lets us do that for the first time in the history of computers," says David Anderson, the SETI team's distributed computing guru. "It lets us, in effect, make them into one big parallel supercomputer."

Moreover, the SETI@home software runs in the background or as a PC screen saver, so it doesn't interfere with users' normal computing tasks.

The search for extraterrestrial intelligence (SETI) may or may not find ET, but it has helped spur a change in thinking about the potential for distributed computing. Proponents say that linking computers through the Internet could enable long-term, computation-intensive tasks in aerodynamics, pharmacology, geophysics, biotechnology and manufacturing to be done in relatively little time.

Suddenly, goals that were once tabled because they were deemed impractical are possible, Anderson says. "There may be some analysis you want to do, and you see it will take 100,000 years of computer time, so you would throw away that idea," he explains. But in one year, SETI@home has used more computer time than that. "So those ideas can be taken out of (the) wastebasket and reconsidered," he says.

Potential users include energy companies that need to do seismic or geographic analyses before they start drilling for oil or digging for coal, manufacturers that do structural analysis or study fluid dynamics prior to transforming a design from a computer model into the real equipment, and engineering firms that stress-test everything from bridges to aircraft.

The basic idea is simple, says Dave McNett, president of Distributed.net, a Birmingham, Alabama-based nonprofit research foundation founded in 1997 to compete in an encryption-breaking contest. The group has grown to 20 developers and has rallied a 190,000-machine network (93 percent are PCs) to break code and solve mathematical puzzles for fun and prizes.

These kinds of networks can accomplish a great deal, McNett says, because 90 percent of most computers' processing power goes unused. Even when computers are in use, the majority of tasks aren't CPU-intensive. Working in a spreadsheet, for example, is CPU-intensive only when the columns are computed.

"CPUs are used only in short bursts," McNett says. "And that's not even mentioning 6 p.m. to 9 a.m. and weekends and holidays."