Oak Ridge National Laboratory’s Summit supercomputer was again named number one on the TOP500 List, a semiannual ranking of the world’s fastest computing systems on Monday, Nov. 12, 2018. (Photo credit: Carlos Jones/Oak Ridge National Laboratory, U.S. Department of Energy)

The 200-petaflop Summit supercomputer at Oak Ridge National Laboratory stayed at number one on the semiannual TOP500 list of the world’s most powerful supercomputers released Monday.

The Sierra supercomputer at Lawrence Livermore National Laboratory in Livermore, California, climbed to number two from number three. That means the United States now has the top two systems in the world, a position that China held a year ago.

Summit, a water-cooled IBM-built supercomputer, debuted at number one on the TOP500 list in June. That was the first time since 2012 that the United States had the most powerful supercomputer in the world. The earlier top system, Titan, a Cray machine, is also located at ONRL. ORNL and LLNL are both U.S. Department of Energy laboratories.

Officials celebrated the launch of Summit in a ceremony attended by U.S. Energy Secretary Rick Perry on June 8. The supercomputer is capable of 200 petaflops, or 200,000 trillion calculations per second. That makes it about about eight times more powerful than Titan, its predecessor.

Besides being the most powerful, Summit has been described as the world’s smartest supercomputer, a machine that can learn. As big as two tennis courts, Summit has 4,608 compute servers. Each has two 22-core IBM Power9 central processing units (CPUs) and six NVIDIA Tesla V100 graphics processing unit (GPU) accelerators. That’s more than 9,000 conventional processors and nearly 28,000 graphics processors, or about 37,000 total. [Read more…]