ACADEMIA

To researchers and engineers, a supercomputer is as essential as a calculator is to an accountant. That's why many took notice when one such computer here won high marks. Currently about 2,000 researchers use the SX-7 annually. Of them, about 30 percent are from outside the university. The SX-7 is up and running 24 hours a day, year-round. However, there is a waiting list of about 100 researchers at all times. The supercomputer at Tohoku University has been drawing national attention ever since it aced a new U.S. performance test in December. The High Performance Computing Challenge (HPCC) test rated the SX-7 the "world's best'' supercomputer for its practicality in quickly solving the kinds of complicated equations used in advanced scientific research. That's a step up from most other supercomputers that are designed to process as many simple calculations as possible within a given period of time. The SX-7 is an essential system used to perform various research at Tohoku University. This includes earthquakes studies, land mine detection and antenna design. Kazuhiro Nakahashi, professor of numerical hydrodynamics at the university's graduate school, is using the supercomputer to research aircraft design. Previously, a large-scale wind tunnel would have been used to calculate the aircraft's ability to lift off and measure wind resistance. Thanks to the SX-7, however, now air currents around an aircraft's body can be simulated in equations and calculated by the supercomputer. "The supercomputer is an essential tool for our research,'' Nakahashi said. "How its performance progresses directly influences the future of our research.'' The SX-7, built by NEC Corp. in 2003, ranked highest in 16 of the HPCC test's 28 categories to win. "Using its incomparable performance as our advantage, we would like to promote the SX-7 across the country,'' said Hiroaki Kobayashi, professor of information science at Tohoku. The SX-7 can crunch 2 trillion calculations per second. That's about 1 million times more than the average household personal computer. In a 300-square-meter room on the second floor of the university's Information Synergy Center building, the hum of internal air conditioners emanates from each of the SX-7's six nodes. Each stands 1.8 meters tall and measures 4-by-3 meters. Two more nodes occupy a 130-square-meter room on the first floor. Each node contains 32 computing units. "The designers of the supercomputer put importance on quality rather than quantity,'' Kobayashi said of the SX-7's ability to whiz through complex equations instead of churn out countless simple calculations. Until the mid 1990s, supercomputers were the so-called vector-type, which uses expensive components exclusively for such machines. A new technology entered the industry about a decade ago. It involves connecting a large number of multipurpose microprocessors that are used in PCs. It made high-speed calculation such as the SX-7's possible. The new technology also had the benefit of cutting the cost of supercomputers nearly in half. It is now used widely. But the processing speeds of this new breed of supercomputers have not been as impressive as expected. Although many could solve simple calculations at relatively high speeds, they have only been able to use a fraction of their capacities to tackle the kind of equations used in advanced and engineering scientific research. SX-7 designers decided not to use the new technology, opting instead for the old vector components. Another factor in the SX-7 being dubbed the world's best supercomputer is that the new HPCC test was made to evaluate practical performance for scientific research over rapidly solving simple calculations. The test measures speeds such as transferring complicated data between computing units. In fact, test makers were thinking along the same lines as SX-7 engineers. Since vector supercomputers are not widely used, however, they can be difficult and costly to obtain. NEC currently makes them for nongovernmental users. Five years ago, for example, there were seven vector-type supercomputers at state-run universities nationwide. Now, the SX-7 is the only such model still in use.