Massively parallel computers: why not parallel computers for the masses?

The developments in high-performance computers towards achieving the goal of a teraflops supercomputer that would operate at a peak speed of 10¹² floating-point operations per second are reviewed. The net result of the quest for parallelism as chronicled by the Gordon Bell Prize is that applications evolved 115% per year and will most likely achieve 1 teraflop in 1995. The physical characteristics of supercomputing alternatives available in 1992 are described. The progress of CMOS microprocessor technology to teraflop speeds is discussed. It is argued that the mainline general purpose computers will continue to be microprocessors in three forms: supercomputers, mainframes, and scalable MPs. The current scalable, multicomputers will all evolve and become multiprocessors, but with limited coherent memories in their next generation. It is also argued that the cost and time to rewrite major applications for one-of-a-kind machines is sufficiently large to make them uneconomical