Updated

China has built the world's fastest computer for a second time, beating the U.S.'s Titan machine.

The semiannual TOP500 official listing of the world's fastest supercomputers says the Tianhe-2 developed by the National University of Defense Technology in Changsha city in central China is capable of sustained computing of 33.86 petaflops per second. That's the equivalent of 33,860 trillion calculations per second. The list was released Monday.

The Tianhe-2 knocks the U.S. Department of Energy's Titan machine off the no. 1 spot. It achieved 17.59 petaflops per second.

It's the second time China has been named as having built the world's fastest supercomputer. In 2010, predecessor Tianhe-1A gained that honor.

Supercomputers are used for complex work such as modeling weather systems, simulating nuclear explosions and designing jetliners.