A new supercomputer from IBM performs calculations five times faster than before - leaving its competitors in the dust. But why is it being used in a Los Alamos nuclear facility? asks Fiona McCann
MEEP! MEEP! The new Roadrunner is faster than ever before, and no eyebrow-wiggling Coyote is going to get near this one. Like its namesake, this Roadrunner lives in the New Mexican desert. But unlike that skinny blue yellow-beaked bird, the new Roadrunner is a $100 million (€65 million) supercomputer, and unlikely to fall for exploding birdseed, given that it is capable of completing 1,000 trillion calculations per second. This makes it a hell of a lot faster than its nearest rival, the suddenly snail-paced Blue Gene/L, which manages a mere 200 trillion operations per second, give or take.
"The computing power available from Roadrunner is staggering," admits Dr Mike Brady from Trinity College Dublin's computer science department. According to its manufacturers, IBM, the Roadrunner runs at petaflop speeds - a confounding new piece of computer-related jargon for those who have only just mastered gigabytes and RAM. "A 'flop' is a 'Floating Point OPeration' - a single calculation involving two numbers with decimal points," says Brady. "The prefix 'peta' means a 1 followed by 15 zeros - 1,000,000,000,000,000 - a million billion, or a thousand trillion. So, IBM claims that the Roadrunner is capable of 1,000,000,000,000,000 numerical calculations every second, which is faster than 100,000 modern laptops."
Pretty fast then, particularly for a computer that was assembled from components originally created for Sony PlayStations. "A few years ago, Sony Toshiba and IBM teamed up to produce a fast new chip to power the then forthcoming PlayStation 3," explains Brady. "The new chip, dubbed the 'Cell', was in fact a tiny supercomputer, with nine separate computer processors, or 'processor cores', on the chip. The huge computing power needed to run a game on the PlayStation 3 is delivered by the nine processor cores dividing up the work so that each core works 'in parallel' on one part of the game. All their results are combined together to animate the game."
It's this notion of dividing up the work to be done so
that a number of different processors can work in tandem that led to the development of the Roadrunner. "This idea of dividing the work up and spreading it around to different processors is not new, and if you can get lots of processors together to work in parallel on a problem, you can build a kind of supercomputer - a 'massively parallel supercomputer'," says Brady.
Which is what IBM has produced for the Los Alamos National Laboratory in New Mexico, as directed by the US Department of Energy's National Nuclear Security Administration. The question is, why? According to the official line, "Roadrunner will primarily be used to ensure the safety and reliability of the nation's nuclear weapons stockpile. It will also be used for research into astronomy, energy, human genome science and climate change."
The New York Times reports that the supercomputer will be used to ensure that America's stockpile of nuclear weapons will continue to work correctly as they age. Brady says a likely use for the Roadrunner within this context would be to run simulations of nuclear explosions "to see what happens to the material that the nuclear bombs are made of . . . If they can simulate the effect it will have on the material, they'll be able to do predictions on how long the nuclear weapons last."
It's not the only avenue of employment for Roadrunner. "The idea is that there are lots of problems out there that you could solve, but you'd need to do zillions and zillions of calculations," says Brady.
"One of them might be weather forecasting. If you think of the atmosphere as a big box, and imagined within it a kind of grid where you had various points, and if you could do calculations at each of these points about things like wind speed, temperature, humidity, and if you could do loads and loads of these calculations, you can predict what would happen next. The more calculations you can do, the finer the grid, and - up to a point - the more precise the prediction can be."
Which all sounds superhumanly impressive. Yet, there is a catch. "To get the most out of a computer like the Roadrunner, you need to write special programs," says Brady. "Normally, programs are written for just one or two processor cores. Modern desktop computers have two, four, or sometimes even eight cores, but the Roadrunner has more than 100,000 cores. So programmers have to figure out ways of solving problems by breaking them up into relatively self-contained sections."
Sound complicated? The point, ultimately, is that no matter how smart, fast and showy computers get, they're still going to require a lot of savvy humans to make them work. "The real kicker, from an academic point of view, is how do you take a problem that you want to solve and how do you break it up in small pieces and give them out to these separate processors so that they work in parallel?" This is the problem that not even a petaflopping Roadrunner can solve, and that requires, despite all the advances, more than a little human input. Which is where we humans, fortunately, can still outwit the Roadrunner.
"Even if you could take advantage of all the power that the Roadrunner has, it's still thousands of times less powerful than the human brain," says Brady. "We still don't know how to programme even a computer like that to make it anything like as flexible, or as powerful, as the human mind."