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“Japanese Computer Is World’s Fastest, As U.S. Falls Back,” read a New York Times headline on April 20, 2002. A Japanese supercomputer had taken the top speed title from the fastest American supercomputers. The writer coined the term, “Computenik,” a reference to the 1957 launch of the first artificial satellite, Sputnik, by the then-Soviet Union, an event which shocked the United States. The term implied that the new Japanese supercomputer sent shockwaves through the U.S. science and technology community on a magnitude not felt since Sputnik. The source of the shockwaves was called the Earth Simulator.
Located in Yokohama, the Earth Simulator is surprisingly massive, taking up a building the size of a small gymnasium in one corner of the campus of the Yokohama Institute for Earth Science, which is part of the Japan Marine Science and Technology Center (JAMSTEC) network. The Earth Simulator is tightly packed in a round shape in a dedicated building, 50m wide and 65m long. Each of the supercomputer’s 640 processor nodes consists of eight vector processors, and each node is connected through 65 networking devices which form the interconnection network at the center of the circular configuration. Outside the circle are peripheral storage devices such as magnetic disks. The Earth Simulator includes these processing nodes, the interconnection network, and the peripheral storage devices. The networking cables under the floor equal a total of some 3,000 km.
The Earth Simulator’s capabilities are, of course, even more impressive than its physical dimensions. It packs a top speed of 40 teraflops, which means 40 trillion floating-point operations per second. That makes this multi-purpose supercomputer the world’s fastest.
“40 teraflops is the Earth Simulator’s theoretical peak performance based on the number and performance rating of each CPU,” explains Kazushige Kikuchi of the Earth Simulator Administrative Office of JAMSTEC’s Yokohama Institute for Earth Science. “When we compare supercomputers, however, we generally look at actual performance. We use the industry-standard Linpack speed-test program to assess this. The Earth Simulator achieves 35.86 teraflops running Linpack, close to 90% of its theoretical peak. This is extraordinary because a supercomputer that can actually achieve just 10–15% of its theoretical peak is generally considered a good performer.”
The previous speed record running the Linpack test was 7.2 teraflops. In other words, in terms of speed actually achieved, the Earth Simulator completely shattered the previous record, beating it by nearly five times. The Earth Simulator project originally targeted actual performance of 5 teraflops on the atmospheric and ocean global model, but repeated refinements during the design stage resulted in speeds farther and farther beyond the original goal.
Supercomputers come in two major varieties—scalar and vector—differentiated by their data-processing method. While scalar supercomputers process data in order, one piece at a time, vector supercomputers can process enormous quantities of data in parallel. The vector architecture is much better suited to simulating natural phenomena, which themselves comprise numerous processes that develop in parallel.
“Meteorological research institutions the world over mainly rely on vector supercomputers,” says Kikuchi. The Earth Simulator is only the leading example of this trend. |
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| A ceremony marking the opening of the JAMSTEC Yokohama Institute for Earth Science was held on August 5, 2002, with the participation of Japan’s Minister of Education, Culture, Sports, Science and Technology and numerous other distinguished guests. Many expressed their hopes that the institute’s Earth Simulator, the world’s fastest supercomputer, would yield ground-breaking research results. |
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