CRAY, SEYMOUR R.

born Sept. 28, 1925, Chippewa Falls, Wis., U.S. died Oct. 5, 1996, Colorado Springs, Colo. American electronics engineer who was the preeminent designer of the large, high-speed computers known as supercomputers. Cray graduated from the University of Minnesota in 1950 with a bachelor's degree in electrical engineering. He began his career as a computer scientist working on UNIVAC I, a landmark first-generation electronic digital computer that became the first commercially available computer. In 1957 Cray helped found Control Data Corp., which became a major computer manufacturer. There Cray designed the CDC 6600 and the CDC 7600, large-scale computers notable for their high processing speeds. In 1972 Cray left Control Data to found his own firm, Cray Research Inc., with the intention of building the fastest computers in the world. This was largely realized through his innovative design of multiprocessor computers, which allowed simultaneous (parallel) processing. His company's first supercomputer, the Cray-1, which came out in 1976, could perform 240,000,000 calculations per second. It was used for large-scale scientific applications, such as simulating complex physical phenomena, and was sold to government and university laboratories. Further supercomputers followed, each with increased computing speed: the Cray 1-M and the Cray X-MP. Cray resigned as chairman of his growing firm in 1981 and became an independent contractor to the company, designing ever-faster machines at his laboratory in Chippewa Falls. In 1985 the Cray-2 was introduced to the market; this machine, which was cooled by Fluorinert, could perform 1,200,000,000 calculations per second. The Cray Y-MP, introduced in 1988, was capable of 2,670,000,000 calculations per second. In 1989 Cray founded the Cray Computer Corporation. However, as microprocessor technology advanced and the demand for supercomputers fell in the post-Cold War era, Cray Computers filed for bankruptcy in 1995.