Eight Playstation 3s used as a supercomputer

An astrophysicist has put together a system made out of eight Playstation 3s to replace a supercomputer, system which he plans on using for solving "a celestial mystery involving gravitational waves and what happens when a super-massive black hole, about a million times the mass of our own sun, swallows up a star."

Dr. Gaurav Khanna uses this cluster of PS3's to measure these theoretical gravity waves - "ripples in space-time that travel at the speed of light" - that Einstein's Relativity Theory predicted would take place in case of such an event.

"The interest in the PS3 really was for two main reasons," explains Khanna, an assistant professor at the University of Massachusetts, Dartmouth who specializes in computational astrophysics. "One of those is that Sony did this remarkable thing of making the PS3 an open platform, so you can in fact run Linux on it and it doesn't control what you do."

He also says that the Cell processors, developed by Sony, IBM and Toshiba, have the massive computing power that could, given proper optimization of the code used, turn them into the equivalent of a supercomputer, making them perfect for the operation at hand.

"The PS3/Linux combination offers a very attractive cost-performance solution whether the PS3s are distributed (like Sony and Stanford's Folding@home initiative) or clustered together (like Khanna's), says Sony's senior development manager of research and development, Noam Rimon.

"It has a general purpose processor, as well as eight additional processing cores, each of which has two processing pipelines and can process multiple numbers, all at the same time," Rimon says.

Prior to obtaining the PS3s, Khanna used various supercomputing sites spread across the United States. "Typically I'd use a couple hundred processors -- going up to 500 -- to do these same types of things."

However, every run of those supercomputers cost Khanna about $5,000. Eight 60 GB PS3 would cost just $3,200, in contrast, but he doubted he could receive a grant from the National Science Foundation (NSF) to buy game consoles, even with the cost difference. So he thought it over and started tweaking code in order to take advantage of the unique architecture in the Cell processor, and then petitioned Sony for some help in the form of free PS3s.

"Once I was able to get to the point that I had this kind of performance from a single PS3, I think that's when Sony started paying attention," Khanna says of his optimized code.

"Khanna says that his gravity grid has been up and running for a little over a month now and that, crudely speaking, his eight consoles are equal to about 200 of the supercomputing nodes he used to rely on."

"Basically, it's almost like a replacement," he says. "I don't have to use that supercomputer anymore, which is a good thing."

"For the same amount of money -- well, I didn't pay for it, but even if you look into the amount of funding that would go into buying something like eight PS3s -- for the same amount of money I can do these runs indefinitely."

"The point of the simulations Khanna and his team at UMass are running on the cluster is to see if gravitational waves, which have been postulated for almost 100 years but have never been observed, are strong enough that we could actually observe them one day. Indeed, with NASA and other agencies building some very big gravitational wave observatories with the sensitivity to be able to detect these waves, Khanna's sees his work as complementary to such endeavors."

- source: Wired.com -