TOKYO (AFP) - A Japanese machine has become the fastest supercomputer in the world, making calculations three times faster than a Chinese rival, its developers said Monday. The K Computer, developed by Fujitsu Ltd. and the state-funded RIKEN institute of physical and chemical research, has achieved 8.162 quadrillion calculations per second (petaflops), they said. One quadrillion is made up of a thousand trillions. It overtook Chinas Tianhe-1A of the National Supercomputing Centre in Tianjin, which became the world number-one in November and is capable of operating at 2.6 petaflops. The K Computers performance was recognised by the authoritative biannual Top500 List of Supercomputers released on Monday at the 2011 International Supercomputing Conference in Hamburg, Germany.