Researchers make calculated bid to retake title for processor speed.
Japanese groups are competing to reclaim for their country the honour of owning the world's fastest supercomputer.
Japan lost the title last autumn, when IBM's BlueGene/L computer — which has a maximum speed of 140 million million calculations per second (140 teraflops) — overtook the Yokohama-based Earth Simulator (see Nature 431, 618; 200410.1038/431618a).