Moore's law

Moore's law is the prediction that the transistor density inside integrated circuits will double every two years, and that prices will decline at the same time. The phenomemon predicted by Moore's law, first described in 1965, has held remarkably true to date, and experts predict that this trend might continue until ~2020 or so, declining at the point where switching element sizes reach the molecular level. Moore's law is not really a law, but rather more a “rule of thumb” or a practical way to think about something.

Moore's law is named for Gordon Moore, a co-founder of Intel, who wrote about it in "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 more uncertain, 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

Although named for him, Gordon Moore may not have invented Moore's law; instead, he may have heard Douglas Engelbart, a co-inventor of the mechanical computer mouse, discuss the projected downscaling of integrated circuit size in a 1960 lecture.. Moore's observation was named a 'law' by the Caltech professor and VLSI pioneer Carver Mead.

In 1975, Moore projected a doubling only every two years. He is adamant that he never said "every 18 months", but that is how it has been quoted. The SEMATECH roadmap follows a 24 month cycle. In April 2005, Intel offered $10,000 for a copy of the original Electronics Magazine.

Versions

The most popular formulation is of the doubling of the number of transistors on integrated circuits (a rough measure of computer processing power) every 18 months. At the end of the 1970s, Moore's Law became known as the limit for the number of transistors on the most complex chips. However, it is also common to use it to refer to the rapidly continuing advance in computing power per unit cost. A similar law has held for hard disk storage cost per unit of information. The rate of progression in disk storage over the past decades has actually sped up more than once, corresponding to the utilization of error correcting codes, the magnetoresistive effect and the giant magnetoresistive effect. The current rate of increase in hard drive capacity is roughly similar to the rate of increase in transistor count and has been dubbed Kryder's Law. However, recent trends show that this rate is falling, and has not been met for the last three years. Another version states that RAM storage capacity increases at the same rate as processing power. However, memory speeds have not increased as fast as CPU speeds in recent years, leading to a heavy reliance on caching in current computer systems.