Japan 'K Computer' Becomes World's Fastest Supercomputer Yet Again

The TOP500 organization has recently published a new list of the world's most powerful supercomputers, and this is for the first time that a system has managed to maintain its position atop the list, as Japan's "K Computer" has emerged yet again as the king of the pack.

"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.

The Japanese-built K Computer is actually so powerful that its performance is four times greater than that of its nearest competitor.

The supercomputer has just recently reached its final configuration which is comprised of 864 racks including a total of 88,128 interconnected CPUs making it able to deliver 10.51 petaflops in the LINPACK benchmark used for calculating the power of HPC systems.

Each of the CPUs installed in the system are specially tuned Fujitsu Sparc64 VIIIfx chips with eight processing cores, a TDP of 58W and a peak performance of 128 GFlops at their 2GHz clock rate.

In order to achieve this results Fujitsu has included a set of extensions developed for high performance clusters which allow applications to manage the CPUs 6MB shared L2 cache.

These instructions also provide support for SIMD, 256 floating point registers per core and carry advanced inter-core hardware synchronization capabilities.

In the K Computer, the chips are linked together with a special interconnect called Tofu that is a 6-D mesh/torus capable of providing 5 GBytes/s of bandwidth and which doesn't require an external switch to be used.

Despite the impressive performance delivered by the system, scientists expect the K Computer to deliver even more performance in the future after they optimize its software for the final hardware configuration used.

The largest US 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.