A supercomputer is a computer that performs at or near the currently highest operational rate for computers. A supercomputer is typically used for scientific and engineering applications that must handle very large databases or do a great amount of computation (or both).
At any given time, there are usually a few well-publicized supercomputers that operate at extremely high speeds. The term is also sometimes applied to far slower (but still impressively fast) computers. Most supercomputers are really multiple computers that perform parallel processing. In general, there are two parallel processing approaches: symmetric multiprocessing (SMP) and massively parallel processing (MPP).
IBM's Roadrunner is the fastest supercomputer in the world, twice as fast as Blue Gene and six times as fast as any of the other current supercomputers. At the lower end of supercomputing, a new trend called clustering, takes more of a build-it-yourself approach to supercomputing. The Beowulf Project offers guidance on how to put together a number of off-the-shelf personal computer processors, using Linux operating systems, and interconnecting the processors with Fast Ethernet. Applications must be written to manage the parallel processing.
Perhaps the best-known builder of supercomputers has been Cray Research, now a part of Silicon Graphics. In September 2008, Cray and Microsoft launched CX1, a $25,000 personal supercomputer aimed markets such as aerospace, automotive, academic, financial services and life sciences. CX1 runs Windows HPC (High Performance Computing) Server 2008.
In the United States, some supercomputer centers are interconnected on an Internet backbone known as vBNS or NSFNet. This network is the foundation for an evolving network infrastructure known as the National Technology Grid. Internet2 is a university-led project that is part of this initiative.