Japan builds world's most powerful supercomputer

A Japanese computer has taken first place on the Top 500 supercomputer list, ending China's reign at the top after just six months. At 8.16 petaflops, the K computer is more powerful than the next five systems combined.

The K computer's performance was measured using 68,544 SPARC64 VIIIfx CPUs each with eight cores, for a total of 548,352 cores, almost twice as many as any other system on the Top500 list. The computer is still under construction, and when it enters service in November 2012 will have more than 80,000 SPARC64 VIIIfx CPUs according to its manufacturer, Fujitsu.

Japan's ascension to the top means that the Chinese Tianhe-1A supercomputer, which took the number 1 position in November last year, is now in second spot with its 2.57 petaflops. But China continues to grow the number of systems it has on the list, up from 42 to 62 systems. The change at the top also means that Jaguar, built for the US Department of Energy (DOE), is bumped down to third place.

The latest iteration of the bi-annual list was released Monday at the 2011 International Supercomputing Conference.

Unlike other recent supercomputers, the K computer doesn't use graphics processors or other accelerators. It uses the most power, but is also one of the most energy efficient systems on the list, according to Top500.org. The supercomputer is installed at the RIKEN Advanced Institute for Computational Science (AICS) in Kobe. When complete, it is intended to run at over 10 petaflops.

This is the first time Japan has had the most powerful supercomputer since the country's Earth Simulator was surpassed by the DOE's IBM BlueGene/L and by Nasa's Columbia in November 2004.

For the first time, all of the top 10 systems achieved performance over 1 petaflop, although they are the only systems on the list that reach that level. The US has five systems in the top 10, Japan and China have two each and France has one.

The DOE's Roadrunner, the first system to break the petaflop barrier in June 2008, is now in tenth place. The performance of computers on the list is measured using the Linpack benchmark, a set of routines that solve linear equations.

The last system on the new list was at position 262 six months ago, meaning almost 48 percent of the list has changed in the last six months, and the turnover rate has steadily increased during the last few lists, according to Top500.org which publishes the list. While performance at the top is advancing by leaps and bounds, movements lower down the list are more modest. The entry point for the top 100 increased to 88.92 teraflops from 75.76 teraflops six months ago.

IBM is the dominant manufacturer on the list with 213 systems in the Top 500, compared to HP with 153.

Intel continues to provide the processors for a majority of the systems on list, followed by AMD and IBM. Intel's Westmere processors are now used by 178 systems, up from 56 systems 6 months ago.

The Top 500 list is compiled by Hans Meuer of the University of Mannheim, Erich Strohmaier and Horst Simon of NERSC/Lawrence Berkeley National Laboratory and Jack Dongarra of the University of Tennessee.