This is an excerpt from EERE Network News, a weekly electronic newsletter.

November 28, 2007

New Organization Provides Efficiency Ranking of Supercomputers

For computer experts focused solely on performance, June and November mark the twice-yearly release of the TOP500 list, which ranks the world's supercomputers in terms of "teraflops," or trillions of calculations per second (the "flop" comes from "floating-point operations," a technical term for computer calculations). That list is currently led by a supercomputer at DOE's Lawrence Livermore National Laboratory (LLNL) that has a peak speed of more than 596 teraflops. But the November 2007 list of supercomputing speed freaks was accompanied by a newcomer, the Green500 list, which reworks the TOP500 list in terms of energy efficiency. The Green500 list ranks the 500 fastest supercomputers by megaflops per watt, that is, by how many thousands of calculations are performed per watt of energy consumed.

On the Green500 list, a research computer run by the United Kingdom's Science and Technology Council takes first place with 357 megaflops per watt, while the LLNL computer drops to 22nd place with only 205 megaflops per watt. But IBM has plenty to crow about in either case, having provided both the LLNL computer and 26 of the 27 top computers on the Green500 list. According to IBM, its Blue Gene/P supercomputers achieve high efficiency through their dense packaging of processors, memory, and interconnects. By the way, the number five supercomputer on the Green500 list is located at DOE's Oak Ridge National Laboratory. See the TOP500 list, the Green500 list, and the IBM press release.

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