A Chinese-built supercomputer is now the fastest such machine in the world, according to a team of researchers that tracks performance of big iron systems.

China's Tianhe-1A system, located at the National Supercomputer Center in Tianjin, achieved a performance of 2.57 petaflops per second. It bested the U.S. Department of Energy's Cray XT5 Jaguar, which previously held top spot with a performance of 1.75 petaflops per second.

China also took third place in the latest rankings with its Nebulae system, which performed at 1.27 petaflops per second. One petaflop is equal to a quadrillion calculations per second.

The rankings, known as Top500, are assembled by researchers at the University of Mannheim in Germany, NERSC/Lawrence Berkeley National Laboratory, and the University of Tennessee in Knoxville.

Overall, they show that the U.S. still holds the dominant share of the world's fastest supercomputers, with 275, but its grip on the market is loosening. "Although the U.S. remains the leading consumer of HPC systems, this number is down from 282 in June 2010," the researchers noted, in a statement.

"The European share—124 systems, down from 144—is still substantially larger than the Asian share (84 systems—up from 57). Dominant countries in Asia are China with 42 systems (up from 24), Japan with 26 systems (up from 18), and India with four systems (down from five)," the researchers said.

The list also shows that supercomputers in general are becoming more powerful. The least powerful system, in 500th place, clocked in at 31.1 teraflops (trillions of calculations per second), compared to 24.7 teraflops in the previous rankings.

The researchers plan to release and discuss the full Top500 list on Nov. 17, at the SC10 Conference on High Performance Computing, Networking, Storage and Analysis, in New Orleans.

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