A K Computer built by Fujitsu out of 68,544 eight-core CPUs at a reported cost of $1.25 billion and 9.89 megawatts of power is now the fastest machine in the world according to the Top5000 Supercomputing List.

It benchmarks at eight quadrillion (8,000 trillion) calculations a second on the Linpack test, dethroning China's three times less powerful 2.6 petaflops/s Tianhe-1A.

It's hard to imagine how fast either of them is but I sure wish I had that many shoes.

An American machine at Oak Ridge National Lab came in third, another Chinese machine came in fourth and a pokey 1.19 petaflops/s Japanese machine came in fifth.

Most of the machines in the Top500 belong to IBM, followed by HP. The US owns 256, by far the most, followed by China with 62 and Germany with 30, the UK with 27, Japan with 26 and France (!) with 25.

It's been six years since Japan led the pack.