Roadrunner Supercomputer Switched Off to Save Power

Dennis Faas's picture

In 2008, IBM's Roadrunner was crowned the fastest computer in the world. Just five years later it's being scrapped.

Roadrunner is based at the Los Alamos National Laboratory in New Mexico, where staff work on several projects, including the U.S. nuclear weapons program.

The computer has some impressive specifications. To put things into context, a new desktop might have the equivalent of two or four processors, perhaps one terabyte (a thousand gigabytes) of hard drive space and four gigabytes of memory.

Computer Performance Second-to-None

Roadrunner has almost 20,000 different processors. It has storage space for more than a million terabytes of data. And its memory is 114,000 gigabytes.

The most impressive aspect of Roadrunner's performance is its speed, however. It was the first supercomputer to consistently run at more than one petaflop. That essentially means it could perform more than a quadrillion (one thousand trillion) calculations per second.

The main benefit of such supercomputers isn't that they can perform a simple calculation incredibly quickly. Instead it is that they can perform a huge number of different calculations in a workable period.

Supercomputers Specialize In Simulations

That makes supercomputers particularly suited to projects that involve simulating processes that involve numerous possible variables, each of which affect one another.

For example, a supercomputer could simulate millions of individual weather events, such as whether a rain cloud passes to the north or south of a mountain range, and then work out all the possible combinations.

That's why some forecasters talk about there being a "70 percent chance" of rain in a particular city rather than simply predicting a show or clear skies.

Roadrunner carried out numerous such tasks, including simulating the way nuclear materials change and decay over time, figuring out how to use extremely thin "nanowires" to focus and harness solar energy, and even simulating the behavior of the entire universe. (Source:

Roadrunner Uses Too Much Juice

Although Roadrunner was ranked the fastest computer in the world from June 2008 to November 2009, it's being decommissioned. That's not simply because it has now been succeeded by much faster machines, with the current record holder seventeen times as quick.

Instead, Roadrunner is now considered too expensive to run compared to newer and more energy efficient machines. To run at full speed, Roadrunner requires 2,345 kilowatts of power.

Including the cost of cooling the computer, its estimated Roadrunner could cost $300 an hour in electricity, or $2.5 million a year. Given that newer supercomputers are five times as energy efficient, it actually works out cheaper in the long run to scrap Roadrunner and build a new machine. (Source:

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