Power isn't everything; Green500 offers new supercomputer list

Computerworld - The most energy-efficient supercomputer on the new Green500 List isn't the top machine on the biannual listing of the most powerful supercomputers in the world -- not by a long shot.

IBM's BlueGene/P system, which is running at the Daresbury Laboratory of the Science and Technology Facilities Council, came out on top of the first official ranking of the Green500. The Daresbury Laboratory  is one of seven national research councils in the U.K. The supercomputer, though a major player on the new green list, is ranked a middling 121 on the latest Top500 List, which was released Nov. 11 at SCO7, a supercomputing conference in Reno, Nev.

The Green500 List  ranks the machines that make the Top500 List by their energy efficiency. The Top500 List ranks the top supercomputers on the planet based on performance.

The BlueGene/P system at the Daresbury Lab produces 357.23 MFLOPS per watt. By comparison, the BlueGene/L system, which still sits at the head of the Top500 List, produces 205.27 MFLOPS per watt. The powerhouse machine, installed at the Lawrence Livermore National Laboratory, takes the No. 22 spot on the Green500.

The Green500 List is the brainchild of two professors at the Virginia Polytechnic Institute and State University, who were looking for a way to commend companies that build energy-efficient supercomputers. 

Kirk Cameron and Wu Feng, both associate professors in the university's computer science department, released the Green500 List of the most energy-efficient supercomputer installations in the world on Thursday. "The list is meant to encourage people to develop systems that use power efficiently," said Cameron, in a previous interview. "If you do that, you decrease costs, which are really high -- between $800,000 and $1 million a year per megawatt. It's ridiculously expensive. You're looking at $1 million to $4 million a year, easily, to run a mega system."

Of the Top500 machines, more than 200 machines directly reported their measured power for the Green500 List, according to an online report. In cases where measured power was not provided, the Green500 List used peak power, as estimated by the Green500 team, based on the best available specifications for the systems in the Top500 List.

Only one of the top 10 supercomputers on the Top500 List made the top 10 in the Green500 List.

BlueGene/P, which is installed at the Forschungszentrum Jülich facility in Jülich, Germany, ranked No. 2 on the Top500 and No. 4 on the Green500. The Jülich Research Centre originally focused on nuclear research, housing three now-defunct nuclear reactors. Today, the center is involved in major grid computing projects.