FACTBOX: World's most powerful computers

LONDON (Reuters) - Britain's most powerful supercomputer was unveiled on Monday.

Here are the world's five fastest computers, listed by name, location and performance in teraflops, or trillions of calculations per second.

1) Blue Gene/L. Lawrence Livermore National Laboratory, California. 478.2 teraflops (TFlop/s).

2) Jugene. Juelich research centre, Germany. 167.3 TFlop/s.

3) SGI Altix ICE 8200. SGI/New Mexico Computing Applications Center, Wisconsin. 126.9 TFlop/s.

4) EKA. Computational Research Laboratories, India. 117.9 TFlop/s.

5) Cluster Platform 3000 BL460c. Unspecified government agency location, Sweden. 102.8 TFlop/s.

(Source: www.top500.org. November 2007)