America's fastest-supercomputer reign has ended, toppled by the Tianhe-2 out of China's National University of Defense Technology.

Tianhe-2 achieved 33.86 petaflop/s on the Linpack benchmark, earning it the title of the world's fastest supercomputer in the world, according to the 41st edition of the twice-annual Top500 List.

Tianhe-2, also known as the Milky Way-2, will be deployed at the National Supercomputer Center in Guangzho, China by the end of 2013  two years ahead of its expected deployment. The machine's achievement marks China's first No. 1 crown since Nov. 2010, when Tianhe-1A was the top system.

"Most of the features of the system were developed in China, and they are only using Intel for the main compute part," Top500 editor Jack Dongarra said in a statement. "That is, the interconnect, operating system, front-end processors and software are mainly Chinese."

The number of systems installed in China has dropped to 66, down from 72 and 68 on the last two lists. As a nation, China also holds the No. 2 position in the performance share, ahead of Japan.

The U.S. may have been knocked from grace, but it didn't fall far. The same two American supercomputers that topped the list in 2012 took second and third place this year: The Sequoia (IBM BlueGene/Q system in the Department of Energy's California-based Lawrence Livermore National 17.59 Pflop/s) and the energy-efficient Titan system (Cray XK7 at Tennessee's Oak Ridge National Laboratory (ORNL)  17.59 Pflop/s).

Fujitsu's "K computer," installed at the RIKEN Advanced Institute for Computational Science (AICS) in Kobe, Japan, is now the No. 4 system, with a performance of 10.51 Pflop/s; a second BlueGene/Q system  Mira  at Argonne National Laboratory is No. 5, with 8.59 Pflop/s.

Notably, this list boasts 26 systems with performance greater than a petaflop/s, up from 23 six months ago. And, according to Top500, the total combined performance of all 500 systems has grown to 223 Pflop/s, compared to 162 six months ago, and 123 one year ago.

Since the last Top500 list was published, the first supercomputer that managed to hit a sustained petaflop in operations-per-second, and one that frequently topped the list of the world's most powerful systems, has been decommissioned.

IBM's Roadrunner, which operated from within the Los Alamos National Laboratory, shut down its 12,960 IBM PowerXCell 8i and 6,480 AMD Opteron dual-core processors, nearly 114 terabytes of memory, and about 1.09 million terabytes of storage, at the end of March. Researchers will continue to run experiments on the machine to determine new methods for compressing operating system memory and optimizing data routing.