Good news for Mother Earth: IBM's Roadrunner, currently the fastest supercomputer in the world, is also one of the most energy-efficient.

That is according to the Top500 supercomputers list released at the International Supercomputing Conference in Dresden, Germany.

Twice yearly, the list measures the 500 most powerful computer systems available commercially. This most recent record is the 31st time the list has been put together.

The Roadrunner, housed at the US Department of Energy's Los Alamos National Laboratory, is the first system to reach 1.026 petaflops (1 petaflop is equal to a quadrillion calculations per second).

Last year's most powerful computer, Lawrence Livermore National Laboratory's BlueGene/L-also made by IBM-reached 208.6 teraflops. This year that computer ranked No. 2, reaching a max processing speed of 478.2 teraflops.

But here's a fun fact: the Roadrunner-used to monitor the US nuclear weapons stockpile-is really just a PlayStation 3 on steroids. Roadrunner is based on the IBM QS22 blades, which are built using advanced versions of the Cell processor in Sony's PS3. It also runs using x86 chips from Advanced Micro Devices, making it the world's first hybrid supercomputer.

In total, Roadrunner takes up 278 refrigerator-size server racks, and connects 6,562 dual-core AMD Opteron and 12,240 Cell chips.

Rounding out the top five systems was the new Sun Microsystems Sun Blade x6420 Ranger system, at 326 teraflops, and the upgraded Cray XT4 Jaguar, at 205 teraflops.