Los Alamos Computer World's Fastest

A supercomputer at Los Alamos National Laboratory remained the world's fastest, narrowly edging out another massive machine at Oak Ridge National Laboratory, according to a twice-yearly ranking of the 500 largest scientific systems.

International Business Machines Corp.'s 188 systems accounted for the most computing power on the so-called Top500 list, and it supplied machines rated first, fourth and fifth. Hewlett-Packard Co. moved past IBM in terms of total systems on the list, with 209 machines. Cray Inc. supplied the No. 2 system and three others in the top 10.

Intel Corp. chips were used in 379 of the top 500 systems. Rival Advanced Micro Devices Inc. supplied chips in 59 machines, including seven of the 10 fastest.

The No. 1 Roadrunner machine at Los Alamos uses both AMD and IBM microprocessors, while the Oak Ridge Jaguar system is powered only by AMD's Opteron chip.

The Top500 list is compiled by researchers at the University of Mannheim, Germany, along with the University of Tennessee in Knoxville, and the Department of Energy's National Energy Research Scientific Computing Center in Berkeley, Calif.