November 2011

Japan’s “K Computer” maintained its position atop the newest edition of the TOP500 List of the world’s most powerful supercomputers, thanks to a full build-out that makes it four times as powerful as its nearest competitor. Installed at the RIKEN Advanced Institute for Computational Science (AICS) in Kobe, Japan, the K Computer it achieved an impressive 10.51 Petaflop/s on the Linpack benchmark using 705,024 SPARC64 processing cores.

The K Computer is the first supercomputer to achieve a performance level of 10 Petaflop/s, or 10 quadrillion calculations per second. In June 2011, the partially built K computer had taken the No. 1 position with a performance of 8.16 Petaflop/s. Contrary to many other recent very large systems, it does not utilize graphics processors or other accelerators. The K Computer is also one of the most energy efficient systems on the list.

Still in second place is the Chinese Tianhe-1A system with 2.57 Petaflop/s performance. One year ago, the Tianhe-1A system took the top spot, but was dethroned when the next TOP500 list was published six months ago.

In fact, the Top 10 supercomputers on the latest list – the 38th edition of the twice-yearly list – remain unchanged from June 2011. The latest list, the data behind it and the trends it reflects will be the topic of a Birds-of-a-Feather session to be held at 5:30 p.m. Tuesday, Nov. 15, at the SC11 supercomputing conference in Seattle.

“This is the first time since we began publishing the list back in 1993 that the top 10 systems showed no turnover,” said TOP500 editor Erich Strohmaier, who will lead the discussion at SC11.

The largest U.S. system is a Cray XT5 system called Jaguar and installed at the Oak Ridge National Laboratory, with a 1.75 Petaflop/s performance running the standard Linpack benchmark application. Other top U.S. systems include Cielo, a Cray XE6 at Los Alamos National Laboratory (No. 6); Pleiades, an SGI Altix machine at NASA’s Ames Research Center (No.7); Hopper, a Cray XE6 at the National Energy Research Scientific Computing Center (No. 8); and Roadrunner, an IBM system that was the first ever to break the Petaflop/s barrier, at Los Alamos (No. 10). Systems in China, Japan and France round out the Top 10.