This is the Grape-DR, a supercomputer housed in the Department of Information Science at the University of Tokyo. It has 64 Intel Core i7-920 processors and an accelerator chip that can achieve 200 gigaflops with a lightbulb's worth of power.
The Grape-DR topped the Little Green500 List of energy-efficient supercomputers, achieving 815.43 MFLOPS per Watt compared to IBM's second place machine, located in Germany, capable of 773.38 MFLOPS per Watt. Only 775 megaflops per Watt? How embarrassing.
The Grape-DR supercomputer, which in addition to be the greenest is apparently also the messiest, pairs its 64 Core i7 processors with four Grape-DR accelerator chips, each of which consumes only 50 watts of power. All together the chips improve the efficiency of the supercomputer five fold.
But being the greenest does not mean fastest - the Grape-DR's peak performance is 23.4 TFLOPS, putting it just shy of 500th place on the top 500 list of the world's fastest supercomputers. That's OK, Grape-DR, you're number 1 in Mother Nature's heart. [TechOn via Technabob]