Explainer

What Is Moore’s Law?

Last month, in Science magazine, a scientist wrote that the computer industry is “in serious danger” of violating Moore’s Law. What is he referring to?

Moore’s Law is really just a prediction that the processing power of the state-of-the-art computer chip will double every 18 months. It’s named after computer engineer Gordon Moore, a co-founder of the Intel Corporation. In 1965, Moore observed that since the invention of integrated circuits (or microchips) in 1959, the number of transistors that a chip of constant surface area could hold had doubled once every year or two. (Integrated circuits are the basic units of computer logic and memory, and transistors are the “on-off” switches that allow digital information to be transmitted, processed, and stored. The more transistors you can pack on a circuit, the more powerful the circuit becomes.) Moore simply predicted that this pattern would continue.

Even though it’s not really a law, Moore’s prediction has held true for the past three decades. In fact, its hallowed status has made it self-fulfilling: Chipmakers and industry analysts now set their goals and forecasts based on Moore’s Law. And because chip prices have decreased even as capacity has risen, the computer processing power available to consumers at a given price has doubled even more quickly.

Since Moore’s Law depends on the continuous shrinking of transistors, scientists generally agree that it will eventually be violated. Previous predictions that it would break down have proved incorrect, and most scientists expect Moore’s Law to hold for at least 10-15 more years. But the Science article suggests that Moore’s Law may encounter physical limits sooner. Transistors have already shrunk to one five-hundredth the width of a human hair. To adhere to Moore’s Law, within five years engineers would have to create transistors that are only a few dozen atoms across–a feat that might be impossible, since atomic movement is so difficult to predict. (Click here to read the New York Times’ non-technical piece on the Science article.) Engineers are currently investigating new materials and technologies that might allow Moore’s Law to survive this latest challenge.

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