By Matthew Dublin
A Japanese supercomputer has knocked a Chinese system from the No.1 spot on the Top500 list. The 37th edition of the Top500 List released today at the International Supercomputing Conference in Hamburg has named Japan's K Computer, which is capable of a whopping 8 petaflops peak performance — that's eight quadrillion calculations per second — as the world's fastest supercomputer. Last year, China caused quite a stir when it claimed the number one ranking with its 2.6 petaflop Tianhe-1A supercomputer at the National Supercomputing Center in Tianjin, as tinges of a Cold War competitiveness colored discussions of the system in the HPC community in the West.
The US now holds third place on the list with the 1.75 petaflop Jaguar supercomputer, a Cray system located at the US Department of Energy's Oak Ridge National Laboratory. The last time Japan was anywhere on the Top500 list was in 2004 with the "Earth Simulator" supercomputer.
The new Japanese system, housed at the RIKEN Advanced Institute for Computational Science in Kobe, was built using homegrown hardware courtesy of Fujitsu. The K Computer combines 68544 SPARC64 VIIIfx CPUs, each with eight cores, for a total of 548,352 cores. Unlike the Tianhe-1A system, the K Computer is a purely CPU-based system and contains no GPUs or other specialized hardware accelerator boards. With almost twice as many cores as any other system in the Top500, the K Computer is actually more powerful than the next five systems on the list combined.
And if an 8 petaflop system isn't impressive enough, the K computer's name is derived from the Japanese word "kei" for ten quadrillions or 10 petaflops, which is the performance goal of the K computer's designers.
A K Computer rack:
While the K Computer does consume almost 10 megawatts of power, for its performance level, it is actually also the most power efficient system on the list. The average power consumption of supercomputers on the list is around 540 kilowatts.
Supercomputers are ranked on the Top500 list according to their performance crunching the Linpack benchmark, a program developed by Jack Dongarra at the University of Tennessee for solving a system of linear equations using matrix computation.