Titan at Oak Ridge National Laboratory stayed at No. 2 in a Top 500 ranking of the world’s most powerful supercomputers released Monday morning. (Photo courtesy of ORNL)

A Chinese supercomputer kept its top ranking, and Titan at Oak Ridge National Laboratory stayed at No. 2 in a Top 500 ranking of the world’s most powerful supercomputers released Monday morning.

The top two spots were unchanged from the semiannual rankings released five months ago in June, when Tianhe-2, a supercomputer developed by China’s National University of Defense Technology, bumped Titan from the top spot. The ORNL supercomputer had been named No. 1 one year ago.

The rankings released Monday at the SC13 conference in Denver, Colo., said Tianhe-2 is capable of performing 33.86 petaflops. That’s 33.86 quadrillion calculations per second, on what is known as a Linpack benchmark test.

Titan is a Cray XK7 system that achieved 17.59 petaflops. Titan is one of the most energy-efficient systems on the list, consuming a total of 8.21 megawatts and delivering 2.143 gigaflops per watt, a press release said. [Read more…]