A year ago, the Department of Energy's Jaguar supercomputer was the fastest in the world, but it has now been relegated to third place.
Still, the United States is tops in overall supercomputer performance, with five systems that can achieve at least one quadrillion calculations per second. Japan and China have just two supercomputers each that can achieve that kind of speed, and France has one.
Jaguar, built by Cray, is located in the DOE's Oak Ridge National Laboratory in Tennessee. It is used for research on climate change, the creation of new materials and atomic energy.
The DOE also has the sixth, eighth and tenth most powerful supercomputers in the world.
NEXT: Pleiades (USA)