IBM's Blue Gene has retained its title as the world's fastest supercomputer in the new Top 500 rankings.

Blue Gene/L has held the accolade since November 2004 and is now capable of performing at a rate of 478.2 teraflops, or 478.2 trillion calculations per second.

The supercomputer is based at California's Lawrence Livermore National Laboratory, where it is used for complicated simulations such as the movement of particles during nuclear fallout.

Second place was awarded to IBM's follow-up computer, Blue Gene/P, one of four new entries in the top five machines. The third spot was taken by the SGI Altix ICE 8200 at the New Mexico Computing Applications Center in Rio Rancho.

India gained its first entry to the top 10 with an HP Cluster Platform 3000 BL460c system, in fourth place. The supercomputer is owned by the Tata business group and installed at the Computational Research Laboratories in Pune.

HP's Cluster Platform also took fifth place and the fourth highest new entry, thanks to strong performance at a government agency in Sweden.

The highest UK entry in the Top 500 was Cray's HECToR at 17, based at the University of Edinburgh.