July 16, 2012, 4:41 PM — The U.S. is once again home to the world's most powerful supercomputer, rebounding after it was knocked out of the top spot by China two years ago and Japan last year.
The latest Top500 list of supercomputers, released last month, also marks a return of European technology in force, as the continent accounted for four of the first 10 systems on the list, and reveals that these ever-powerful computers are increasingly used for commercial purposes.
Even though U.S. technology has dominated the Top500 rankings since researchers first compiled the list in 1993, the two-year absence from the top spot had hit a national nerve.
President Barack Obama mentioned China's top-ranked supercomputer in two separate speeches, including last year's State of the Union address, and Secretary of Energy Steven Chu, a Nobel Prize winner in physics, warned that America's innovation leadership was at risk.
Though competitive threats to U.S. technology leadership remain -- for example, China launched its fourth manned space mission in June, just months after the U.S. ended its shuttle program -- the U.S. is back on top of the supercomputer world, at least for now.
The Linux-based IBM Sequoia system that tops the latest list is powered by Power BQC 16-core processors running at 1.6GHz, and mostly relies on architecture and parallelism, not Moore's Law, to achieve speeds of 16.32 sustained petaflops. Sequoia, an IBM BlueGene/Q, is installed at the U.S. Department of Energy's Lawrence Livermore National Laboratory.
"We're at the point where the processors themselves aren't really getting any faster," said Michael Papka, deputy associate director for computing, environment and life sciences at the DOE's Argonne National Laboratory, which runs a similar IBM system that placed third on the list. "Moore's Law is generally slowing down and we're [getting faster speeds] by parallelism."
"The classic trick of waiting for Moore's Law to come along and help you out really doesn't exist anymore," added David Turek, vice president of exascale computing at IBM.
Both the Sequoia supercomputer and the Mira system housed at the Argonne lab are among the first IBM supercomputers to use water-cooling technology.


















