Tianhe-2, a supercomputer developed by the National University of Defense Technology, topped the world's fastest supercomputer list released by TOP 500, a project ranking the 500 most powerful computer systems worldwide, in Leipzig, Germany, on June 17. The supercomputer, capable of performing 33.86 quadrillion operations per second--or petaflops in industry parlance, allowed China to regain the top spot after two and a half years.

Experts said Tianhe-2, whose speed is nearly twice that of the runner-up, may enable China to stay at the top for at least a year. In the future, China, the United States, Japan and Europe are likely to take turns holding the top position.

Homemade components

Tianhe-2 is located in the Changsha-based National University of Defense Technology. The imposing supercomputer, consisting of 170 refrigerator-size blue cabinets, covers an area of 720 square meters.

Hu Qingfeng, Deputy Chief Designer of Tianhe-2, said, "It will take 1.3 billion calculator users 1,000 years to finish the computing Tianhe-2 does in just an hour. The supercomputer's total data storage volume is equivalent to 60 billion copies of 100,000-character books."

In a research report filed after an on-site inspection of Tianhe-2 in May, Jack Dongarra, a TOP 500 editor and a professor at the University of Tennessee, said standard tests showed the speed of Tianhe-2 was 74 percent faster than that of Titan, the former champion made by the United States. Tianhe-2 exhibits distinctive Chinese characteristics, with its network system, operating system, front-end processors and software mainly developed by Chinese researchers, he added.

The U.S.-based PC World magazine noted the United States will lose its leadership status unless it spends billions of dollars in developing exascale supercomputers with a computing performance in the range of exaflops, or 1,000 petaflops. The magazine said China is working toward building a supercomputer with all components made at home, including 100 percent of its chips.

While most of the chips in Tianhe-2 are from Intel Corp., the Chinese supercomputer uses about 4,000 domestically produced chips, a sign that reliance on foreign technology is being reduced, said Horst Simon, Deputy Director of the U.S. Lawrence Berkeley National Laboratory. "In some areas where there has been a tradition of U.S. leadership, the Chinese are out there to really be in the race and win," he said, adding that the next U.S. supercomputer that could challenge Tianhe-2 isn't expected until 2015.

"If anybody believes that the Chinese are just in there for a stunt, this machine has proven them wrong," Simon said. "In some sense, it's a wake-up call to the United States."

Independent innovation

At the 2013 International Supercomputing Conference in Leipzig in June, Tianhe-2 won huge applause for its performance.

The supercomputer has 1,400 terabytes of memory and 12,400 terabytes of total data storage capacity with a maximum power of 17.8 megawatts. Its speed, 33.86 petaflops, is twice that of Titan, while its computing density--computing capacity per unit of area occupied--is 2.5 times that of the U.S. supercomputer previously ranked as the world's fastest. Its performance per unit of energy consumed is almost the same as Titan's.

German weekly newsmagazine Der Spiegel said that compared with Tianhe-2, which is capable of operating at almost twice its speed, previous world champion Titan was as slow as an abacus.

China returned to the top of the supercomputing world with a performance far exceeding the runner-up after it lost the position in the fall of 2010, said Asahi Shimbun. The Japanese newspaper reported that Tianhe-2's technology won high recognition from experts.

Li Nan, Deputy Commander in Chief of the Tianhe-2 project, said the supercomputer's high performance and energy efficiency are a result of independent innovation aimed at developing cutting-edge technology, a driving force behind the rapid development of China's supercomputing technology.

The history of supercomputing shows systemic innovation and breakthroughs in a series of key technologies are needed to upgrade computing power to a new scale. In Tianhe-1, Tianhe-2's predecessor, researchers for the first time adopted an integrated heterogeneous computing structure characterized by a combination of central processing units and graphics processing units, a move that charted the future course of supercomputing technology.

Tianhe-1 became the first Chinese supercomputer to make it to the top of the list in November 2010. But only six months later, it was surpassed by the K computer developed by Japan's RIKEN. In June and November last year, U.S. supercomputers Sequoia and Titan respectively topped the list, with Tianhe-1 dropping to eighth place.

How long can Tianhe-2 lead the pack? "Surpassing each other will probably become the norm in the competition among the world's supercomputing powers," Li said.

Fierce competition

Supercomputing researchers across the world share the belief that it is difficult to develop supercomputers, but it is even more difficult to make good use of them, said Zhu Xiaoqian, Deputy Chief Designer of Tianhe-2. While working on Tianhe-2, Chinese researchers reviewed and analyzed experience in developing and applying Tianhe-1. They also conducted in-depth research on market demand.

Tianhe has assisted with the production of movies and TV series such as Chinese movie The Lost Bladesman, a new version of Chinese TV drama Journey to the West and U.S. movie Resident Evil: Apocalypse, all of which have long been shown at cinemas and on TV. The example shows how supercomputers can be put into practical use.

"Supercomputing is a strategic high ground of sophisticated technology and a symbol of a country's technological competiveness and comprehensive national power," said Liao Xiangke, Commander in Chief of the Tianhe-2 project and Chief Designer of Tianhe-2.

Satoshi Matsuoka, a professor with the Tokyo Institute of Technology, said on June 17 that thanks to its breakthroughs in supercomputing technology, China is likely to remain at the top in the next two years. Supercomputer development has now entered an era dominated by the United States, Japan, Europe and China, he added.

Bill Bader, a California-based computer engineer, told People's Daily that supercomputers symbolize a country's competitiveness. The fact that China developed two of the fastest supercomputers in less than three years highlights the country's remarkable technological progress, he said.

At the same time, Bader noted the United States took up more than 250 entries on the TOP 500 list, suggesting the U.S. is still the country where supercomputers are most widely applied. Japan and Europe are also highly competent, he said, adding that there will be fierce international competition in the years ahead.