IBM has built the world's fastest supercomputer, a machine that can operate at one petaflop, which is 1,000 trillion floating point operations per second.
This is twice as fast as IBM Blue Gene, the world's previous fastest computer.
Called "Roadrunner", the new supercomputer has been built for the US Department of Energy's National Nuclear Security Administration.
It will mainly be used for US nuclear weapons simulations, but it will also be used for research in areas such as energy, astronomy, human genome science and climate change.
The computer runs on Red Hat Linux and uses a mixture of processors.