Japanese ‘K’ Computer Is Ranked Most Powerful

In the rankings of the world’s most powerful supercomputers, a Japanese machine has earned the top spot with a performance that essentially laps the competition.

The computer, known as “K Computer,” is three times faster than a Chinese rival that previously held the top position, said Jack Dongarra, a professor of electrical engineering and computer science at the University of Tennessee at Knoxville who keeps the official rankings of computer performance.

K, built by Fujitsu and located at the Riken Advanced Institute for Computational Science in Kobe, Japan, represents a giant leap forward in speed. It will also undoubtedly be a source of national pride for Japan, at least among computer scientists, who take the race for fastest computer quite seriously.

“It’s a very impressive machine,” Mr. Dongarra said. “It’s a lot more powerful than the other computers.”

The latest ranking of the top 500 computers, to be released later today(Monday), is determined by running a standard mathematical equation. The winning computer was able to make 8.2 quadrillion calculations per second, or in more technical terms, 8.2 petaflops per second.

The performance of K is equivalent to linking around one million desktop computers, Mr. Dongarra said.

Supercomputers are used for earthquake simulations, climate modeling, nuclear research and weapons development and testing, among other things. Businesses also use the machines for oil exploration and rapid stock trading.

Building supercomputers is costly and involves connecting thousands of small computers in a data center. K is made up of 672 cabinets filled with system boards. Although considered energy-efficient, it still uses enough electricity to power nearly 10,000 homes at a cost of around $10 million annually, Mr. Dongarra said.


The research lab that houses K plans to increase the computer’s size to 800 cabinets. That will raise its speed, which already exceeds that of its five closest competitors combined, Mr. Dongarra said.

“K” is short to the Japanese word “Kei,” which means 10 quadrillion, the ultimate goal for the number of calculations the computer can perform per second.

K succeeded in pushing the previous leader, China’s Tianhe-1A supercomputer, at the National Supercomputing Center in Tianjin, China, to second place. Tianhe-1A had been the first Chinese computer to be ranked on top, signaling the country’s growing technological might.

The fastest computer in the United States, at Oak Ridge National Laboratory, in Oak Ridge, Tenn., placed third.

Asian countries have made huge investments in supercomputing and now dominate the upper echelon of the field. Japan and China hold four of the top five spots in the latest ranking.

However, in terms of the top 10, the United States remains the leader with five computers. They are at government research facilities.

Japan’s top supercomputer ranking is its first since 2004. The United States and China are the only other countries to have held the title.

The rankings, which are issued every six months, change frequently and reflect how fast computer power is advancing. For example, the top ranked computer in June 2008, at Los Alamos National Laboratory in New Mexico, is now in 10th place.

Mr. Dongarra said a computer called Blue Waters, being developed at the University of Illinois at Urbana-Champaign, may rival K in speed.