Effect of increasing chip density on the evolution of computer architectures

Trends in lithography and process technology indicate that billion-transistor computer chips will be possible well before the end of the decade. Such a large number of transistors could be used to implement dynamic learning techniques to improve the performance of a processor for many applications. However, the efficiency of use of transistors in this manner is not high. A more attractive use of the available transistors is to bring more of the entire system onto the chip, and this paper examines two different approaches for doing so. The first involves bringing memory closer to the processors in a symmetric multiprocessor cell, and using these cells in a regular organization with a programmable interconnection to create powerful computers. The second involves integration on the same chip of varied structures such as processors, DRAM, sensors, and transducers, which in the past required different processing capabilities-commonly referred to as the System-on-a-Chip approach. The paper describes the exciting options offered by both approaches and discusses the implications of each for programming and tool development.