Some of the technology that will drive the advances of the 1990s are explored. A brief tutorial is given to explain the fundamental speed limits of metal interconnections. The advantages and disadvantages of optical interconnections and where they may be used are discussed in some detail. Trends in speeding up performance by increasing data-path width and by increasing the number of operations performed are reviewed, and questions of efficiency are examined. The advent of super reliable machines produced at very low cost by replicating entire processors is examined. >