Plot of transistor counts against dates of introduction. The curve shows counts doubling every two years.
Moore's law describes a long-term trend in the history of computing hardware. Since the invention of the integrated circuit in 1958, the number of transistors that can be placed inexpensively on an integrated circuit has increased exponentially, doublingapproximately every two years. The trend was first observed by Intel co-founder Gordon E. Moore in a 1965 paper. It has continued for almost half of a century and is not expected to stop for another decade at least and perhaps much longer.
Almost every measure of the capabilities of digital electronic devices is strongly linked to Moore's law: processing speed, memory capacity, even the number and sizeof pixels in digital cameras. All of these are improving at (roughly) exponential rates as well. This has dramatically increased the usefulness of digital electronics in nearly every segment of the world economy. Moore's law describes this driving force of technological and social change in the late 20th and early 21st centuries.
Predictions of similar increases in computer power hadexisted years before Moore published his observation. Alan Turing in a 1950 paper had predicted that by the turn of the century, computers would have a billion words of memory. Moore may have heard Douglas Engelbart, a co-inventor of today's mechanical computer mouse, discuss the projected downscaling of integrated circuit size in a 1960 lecture.
Moore's original statement that transistorcounts had doubled every year can be found in his publication "Cramming more components onto integrated circuits", Electronics Magazine 19 April 1965:
The complexity for minimum component costs has increased at a rate of roughly a factor of two per year ... Certainly over the short term this rate can be expected to continue, if not to increase. Over the longer term, the rate of increase is a bit moreuncertain, although there is no reason to believe it will not remain nearly constant for at least 10 years. That means by 1975, the number of components per integrated circuit for minimum cost will be 65,000. I believe that such a large circuit can be built on a single wafer.
The term "Moore's law" was coined around 1970 by the Caltech professor, VLSI pioneer, and entrepreneur Carver Mead.
Mooreslightly altered the formulation of the law over time, bolstering the perceived accuracy of Moore's Law in retrospect. Most notably, 1975, Moore altered his projection to a doubling every two years. Despite popular misconception, he is adamant that he did not predict a doubling "every 18 months". However, an Intel colleague had factored in the increasing performance of transistors to concludethat integrated circuits would double in performance every 18 months.
In April 2005, Intel offered $10,000 to purchase a copy of the original Electronics Magazine. David Clark, an engineer living in the UK, was the first to find a copy and offer it to Intel.
Other formulations and similar laws
PC hard disk capacity (in GB). The plot is logarithmic, so the fitted linecorresponds to exponential growth.
Pixels per dollar based on Australian recommended retail price of Kodak digital cameras
Several measures of digital technology are improving at exponential rates related to Moore's law, including the size, cost, density and speed of components. Moore himself wrote only about the density of components (or transistors) at minimum cost.
Transistorsper integrated circuit. The most popular formulation is of the doubling of the number of transistors on integrated circuits every two years. At the end of the 1970s, Moore's law became known as the limit for the number of transistors on the most complex chips. Recent trends show that this rate has been maintained into 2007.
Density at minimum cost per transistor. This is the formulation given...