For only the second time in 24 years, the US has been edged out of the top flight of the world's most powerful number-crunchers.
An upgrade to a Swiss supercomputer has bumped the US Department of Energy's Cray XK7 to number four on the list rating these machines.
The only other time the US fell out of the top three was in 1996.
Chinese supercomputers currently occupy the top two slots in the respected Top 500 list.
Power curve
The US machine has been supplanted by Switzerland's Piz Daint system, which is installed at the country's national supercomputer centre.
The upgrade boosted its performance from 9.8 petaflops to 19.6.
The machine is named after a peak in the Grison region of Switzerland.
One petaflop is equal to one thousand trillion operations per second.
A "flop" (floating point operation) can be thought of as a step in a calculation.
Supercomputers are often used to carry out incredibly detailed simulations, handle weather forecasts and tackle problems in physics, computational science and geophysics.
The performance improvement meant it surpassed the 17.6 petaflop capacity of the DoE machine, located at the Oak Ridge National Laboratory in Tennessee.
The US is well represented lower down in the list, as currently half of all the machines in the top 10 of the list are based in North America.
More:
http://www.bbc.co.uk/news/technology-40325237Of course, the list is only computers people
know about ....
