A newly built supercomputer in China appears poised to take the world performance lead, another sign of the country's growing technological prowess that is likely to set off alarms about U.S. competitiveness and national security. The system was designed by China's National University of Defense Technology and is housed at the National Supercomputing Center in the city of Tianjin. It is part of a new breed that exploits graphics chips more commonly used in playing videogames―supplied by Nvidia Corp. ―as well as standard microprocessors from Intel Corp.