Moore's Law
Moore's law is an empirical observation stating, in effect, that at our rate of technological development and advances in the semiconductor industry, the complexity of integrated circuits doubles every 18 months. See exponential growth.
It is attributed to Gordon E. Moore (a co-founder of Intel, not to be confused with the philosopher G. E. Moore). Moore outlined his "law" in 1965. His original empirical observation was that the number of components on semiconductor chips with lowest per-component cost doubles roughly every 12 months, and he conjectured that the trend will stay for at least 10 years. In 1975, Moore revised his estimate for the expected doubling time, arguing that it was slowing down to about two years (see the external link below).
Formulations of Moore's law
The "law" has been formulated in numerous redactions that are sometimes only loosely linked to Moore's initial observation and less well-motivated empirically:
- Moore's original statement, made in 1965 while he was Director of Fairchild Semiconductor's Research and Development Laboratories, was published in a paper in the 35th Anniversary Issue of Electronics magazine. The complexity for minimum component cost has increased at roughly a factor of two per year. Certainly over the short term this rate can be expected to continue, if not increase. The press soon dubbed this "Moore's Law".
- 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.
- It is also common to cite Moore's law to refer to the rapidly continuing advance in computing power per dollar cost.
- A similar progression has held for hard disk storage available per dollar cost - in fact, the rate of progression in disk storage over the past 10 years or so has actually been faster than for semiconductors—although, largely because of production cost issues, hard drive performance increases have lagged significantly.
- Another version claims 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.
Historical analysis of Moore's law has shown that its interpretations have qualitatively changed over the years and that it has not very accurately described developments in semiconductor technology. For example, CPU monthly shows a month-by-month display of Top Processors from Intel and AMD which gives relatively little justification for believing the law continues to operate as stated.
The evident appeal of the concept, the proliferation of formulations, its tendency to self-replicate in each technology generation, and the evolution of new interpretations is characteristic of a meme.
An industry driver
Although Moore's law was initially made in the form of an observation and prediction, the more widely it became accepted the more it served as a goal for an entire industry - driving both marketing and engineering departments within semiconductor manufacturers to focus enormous energy aiming for the specified increase in processing power that it was presumed one or more of their competitors would soon actually attain. In this regard it can be viewed as a self-fulfilling prophecy. However, just as the "law" has itself taken on mythic status somewhat independent of actual facts, its significance to technology growth may be prone to a degree of mythologising.
The implications of Moore's law for computer component suppliers is very significant. A typical major design project (such as an all-new CPU or hard drive) takes between two and five years to reach production-ready status: in consequence, component manufacturers face enormous timescale pressures: just a few weeks delay in a major project can spell the difference between great success and massive losses, even bankruptcy.
Expressed as "a doubling every 18 months", Moore's law suggests the phenomenal progress of technology in recent years. Expressed on a shorter timescale, however, Moore's law equates to an average performance improvement in the industry as a whole of over 1% a week. For a manufacturer competing in the cut-throat CPU, hard drive or RAM markets, a new product that is expected to take three years to develop and is just two or three months late is 10 to 15% slower or larger in size than the directly competing products, and is usually unsellable.
Future trends
Current PC processors work at the 130 nm level, and a 90 nm chip has recently been announced. Companies are working on using nanotechnology to solve the complex engineering problems involved in producing chips at the 45 nm, 30 nm, and even smaller levels -- a process that will postpone the industry meeting the limits of Moore's Law.
Recent computer predict (as of 2001) that Moore's Law will continue for several chip generations. Depending on the doubling time used in the calculations, this could mean up to 100 fold increase in transistor counts on a chip in a decade. The semiconductor industry technology roadmap uses a three-year doubling time for microprocessors, leading to about nine-fold increase in a decade.
Since the rapid exponential improvement could put 100 GHz personal computers in every home and 20 GHz devices in every pocket, some commentators have speculated that sooner or later computers will meet or exceed any conceivable need for computation. This is only true for some problems - there are others where exponential increases in processing power are matched or exceeded by exponential increases in complexity as the problem size increases. See computational complexity theory and complexity classes P and NP for a (somewhat theoretical) discussion of such problems, which occur very commonly in applications such as scheduling.
Extrapolation based on Moore's Law has led futurists such as Vernor Vinge and Bruce Sterling to speculate about a technological singularity.
Other considerations
Note that not all aspects of computing technology develop in capacities and speed according to Moore's Law. Random Access Memory speeds, and hard drive seek times improve at best at a few percentage points per year.
Another, sometimes misunderstood, point is that exponentially improved hardware does not necessarily imply exponentially improved software to go with it. The productivity of software developers most assuredly does not increase exponentially with the improvement in hardware, but by most measures has increased only slowly and fitfully over the decades.
