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Exponential Laws of Computing Growth

Exponential Laws of Computing Growth, illustration

Credit: Peter Crowther Associates

In a forecasting exercise, Gordon Earle Moore, co-founder of Intel, plotted data on the number of components—transistors, resistors, and capacitors—in chips made from 1959 to 1965. He saw an approximate straight line on log paper (see Figure 1). Extrapolating the line, he speculated that the number of components would grow from 26 in 1965 to 216 in 1975, doubling every year. His 1965–1975 forecast came true. In 1975, with more data, he revised the estimate of the doubling period to two years. In those days, doubling components also doubled chip speed because the greater number of components could perform more powerful operations and smaller circuits allowed faster clock speeds. Later, Moore's Intel colleague David House claimed the doubling time for speed should be taken as 18 months because of increasing clock speed, whereas Moore maintained that the doubling time for components was 24 months. But clock speed stabilized around 2000 because faster speeds caused more heat dissipation than chips could withstand. Since then, the faster speeds are achieved with multi-core chips at the same clock frequency.

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Key Insights


Moore's Law is one of the most durable technology forecasts ever made.10,20,31,33 It is the emblem of the information age, the relentless march of the computer chip enabling a technical, economic, and social revolution never before experienced by humanity.


Domenico Ponta

Excellent article, a more comprehensive and thorough view of the Moore's law. The authors' statement "We will conclude that Moore's Law and exponential doubling have scientific bases." seems a bit too strong, though.

CACM Administrator

Co-authors Peter J. Denning's and Ted G. Lewis' comment follows here.
--CACM Administrator

Figures 1 thru 4 are strong evidence that Moore's law has held for 60 years. We ourselves were initially skeptical that Moore's 1965 empirical observation is a law. That it has held for so long across multiple families of technologies, however, suggested that it is more than a self-fulfilling prophesy. When we looked more closely at empirical evidence (Figures 1-4), we concluded that engineers were harnessing recurrent physical effects unique to computing technologies. We further concluded from the mathematics that exponential rates of adoption are normal and that technology jumping enables those rates to continue with a new technology when an older one hits its limits. There are plenty of technologies ripening for possible jumps including clever new transistors, quantum dots, memristors, and quantum computers. There is plenty of science backed up with empirical validation to confirm Moore's law. Expect Moore's law for computing power and energy efficiency to continue for many more generations of computing technologies.

--Peter J. Denning and Ted G. Lewis

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