China has topped the list of the twice-annual ranking of the world's most powerful supercomputers, replacing the United States. In the latest ranking the Tianjin National Supercomputer Center's Tianhe-1A system benchmarked a performance of 2.67 petaflops (quadrillion floating-point calculations per second), surpassing the former top achiever, the U.S. Department of Energy (DOE) Oak Ridge Leadership Computing Facility's Cray XT5 Jaguar system, which clocked in at 1.75 petaflops in this round.

China’s arrival to the top place puts an end to a six-year domination of America which started when the DOE's IBM BlueGene/L system beat Japan's Earth Simulator system, built by NEC. At that time the existence of the Earth Simulator system itself was the source of much consternation on the part of the U.S. Congress, which set aside money for the DOE to build systems that would re-establish the country's lead in high-performance computing.

It is yet to be seen if the US will react the same way to the Chinese growing technology strength.

The TOP500 list is compiled twice a year by researchers at the University of Mannheim, Germany; the DOE's Lawrence Berkeley National Laboratory; and the University of Tennessee, Knoxville. Participation, which is voluntary, requires that the computer run the Linpack benchmark, a set of routines that solve linear equations.

In this iteration, seven systems achieved a performance of 1 petaflop or better. Three of these systems reside in the U.S., two in China, and one each in France and Japan.