on one powerful central processing unit to search through all of the separate addresses where a bit memory might be stored in a serial computer, the Connection Machine employs up to 65,536 simpler processors (in its present incarnation), each with a small memory of its own. Any one processor can be assigned a distinct task—for example, to attend to a distinct point or pixel in an image—and they can all function at once, independently. And of particular value, any one processor can communicate with any other and modify its own information and task pursuant to such a communication. The pattern of their connections also facilitates much shorter information routes: tasks proceed through the machine essentially analyzing the best route as they proceed. The comparatively "blind" logic of serial machines possesses no such adaptable plasticity. "Each processor is much less powerful than a typical personal computer, but working in tandem they can execute several billion instructions per second, a rate that makes the Connection Machine one of the fastest computers ever constructed," wrote Hillis (1987, p. 108).

Speed, cost per component, and cost per calculation have been the currencies by which computers have been evaluated almost from their inception, and each successive generation has marked exponential improvement in all three standards. Nonetheless, Smarr believes the industry is approaching a new level of supercomputing unlike anything that has gone before: "By the end of the 20th century, price drops should enable the creation of massively parallel supercomputers capable of executing 10 trillion floating-point operations per second, 10,000 times the speed of 1990 supercomputers," This astounding change derives from the massively parallel architecture, which "relies on the mass market for ordinary microprocessors (used in everything from automobiles to personal computers to toasters) to drive down the price and increase the speed of general-design chips. Supercomputers in this new era will not be confined to a single piece of expensive hardware located in one spot, but rather will be built up by linking "hundreds to thousands of such chips together with a high-efficiency network," explained Smarr.

BIBLIOGRAPHY

Harel, David. 1987. Algorithmics: The Spirit of Computing. Addison-Wesley, Reading, Mass.

Hillis, W. Daniel. 1987. The connection machine. Scientific American 256(June):108–115.


Pagels, Heinz R. 1988. The Dreams of Reason: The Computer and the Rise of the Sciences of Complexity. Simon and Schuster, New York.



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