Modern Day Xeno: Moore's "Law" Doesn't Exist

[R. A. Hettinga]

http://firstmonday.org/issues/issue7_11/tuomi/index.html


First Monday

The Lives and Death of Moore's Law by Ilkka Tuomi

Abstract

Moore's Law has been an important benchmark for developments in
microelectronics and information processing for over three decades. During
this time, its applications and interpretations have proliferated and
expanded, often far beyond the validity of the original assumptions made by
Moore. Technical considerations of optimal chip manufacturing costs have
been expanded to processor performance, economics of computing, and social
development. It is therefore useful to review the various interpretations
of Moore's Law and empirical evidence that could support them.

Such an analysis reveals that semiconductor technology has evolved during
the last four decades under very special economic conditions. In
particular, the rapid development of microelectronics implies that economic
and social demand has played a limited role in this industry. Contrary to
popular claims, it appears that the common versions of Moore's Law have not
been valid during the last decades. As semiconductors are becoming
important in economy and society, Moore's Law is now becoming an
increasingly misleading predictor of future developments.

Contents

1. Introduction
2. Moore's original formulation
3. Reformulations of Moore's Law
4. Losing the memory
5. Empirical evidence on Moore's Law
6. Computers and development

 

 

1. Introduction

In 1965, Gordon Moore, Director of Fairchild Semiconductor's Research and
Development Laboratories, wrote an article on the future development of
semiconductor industry for the 35th anniversary issue of Electronics
magazine. In the article, Moore noted that the complexity of minimum cost
semiconductor components had doubled per year since the first prototype
microchip was produced in 1959. This exponential increase in the number of
components on a chip became later known as Moore's Law. In the 1980s,
Moore's Law started to be described as the doubling of number of
transistors on a chip every 18 months. At the beginning of the 1990s,
Moore's Law became commonly interpreted as the doubling of microprocessor
power every 18 months. In the 1990s, Moore's Law became widely associated
with the claim that computing power at fixed cost is doubling every 18
months.

Moore's Law has mainly been used to highlight the rapid change in
information processing technologies. The growth in chip complexity and fast
reduction in manufacturing costs have meant that technological advances
have become important factors in economic, organizational, and social
change. In fact, during the last decades a good first approximation for
long-range planning has often been that information processing capacity is
essentially free and technical possibilities are unlimited.

Regular doubling means exponential growth. Exponential growth, however,
also means that the fundamental physical limits of microelectronics are
approaching rapidly. Several observers have therefore speculated about the
possibility of "the end of Moore's Law." Often these speculations have
concluded by noting that Moore's Law will probably be valid for at least "a
few more generations of technology," or about a decade. An important
example is the International Technology Roadmap for Semiconductors (ITRS),
which now extends to 2016. This roadmap is generated by a global group of
experts and represents their consensus. Although it notes that within the
next 10-15 years "most of the known technological capabilities will
approach or have reached their limits," its basic assumption is that
Moore's Law, although perhaps slowing down, still provides a good basis for
predicting future developments in the semiconductor industry (ITRS, 2001) [
1].

Of course, if Moore's Law is valid, independent of the exact nature of
physical limits, exponential development means that the limits are only a
few technological generations ahead. Order of magnitude errors in our
current estimates of the ultimate limits of chip technology will create at
most a few months of error in the time when they become bottlenecks in chip
technology [ 2]. As a result, it is easy to predict that Moore's Law will
become invalid soon. Speculations on the extended lifetime of Moore's Law
are therefore often centered on quantum computing, bio-computing, DNA
computers, and other theoretically possible information processing
mechanisms. Such extensions, obviously, extend beyond semiconductor
industry and the domain of Moore's Law. Indeed, it could be difficult to
define a "component" or a "chip" in those future devices.

Although discussion on physical limits, bottlenecks, and alternative
information processing models may be important for chip manufacturers, it
is, however, not the focus of this paper. Instead, I shall argue that there
is no end to Moore's Law in sight simply because it never accurately
described developments in microelectronics. It never was valid.
Furthermore, it neglected factors that are becoming increasingly visible
and important.

The present paper argues that Moore's Law has not been a driver in the
development of microelectronics or information technology. This may come as
a surprise to some who have learned that Moore's Law has become a
self-fulfilling prophecy that semiconductor industry firms have to follow
if they want to survive. Instead, I shall argue that technical development
in semiconductors during the last four decades has reflected the unique
economic and social conditions under which the semiconductor industry has
operated. This is important as these conditions are changing. In short, the
observed technological trends and their analysis indicate that the
semiconductor industry has been a core element in an industry cluster where
development to an important extent has been driven by intra-cluster forces.
The semiconductor industry, in other words, has been a laboratory of
endogenous growth.

This laboratory of endogenous growth has also made many failed experiments.
Technology has not evolved in the ways predicted by Moore. Moore's Law has
become popular partly because it has allowed great flexibility in
interpretation and selective choice of supporting data. In this process,
Moore's Law and evidence for it have retrospectively been interpreted to
establish the validity of the Law. Often the presented evidence has been in
visible contradiction with the Law.

Technological advances in silicon chips have been relatively independent of
end-user needs. During the last three decades, a good approximation in this
industry has been that the supply of technology determines development. In
economic terms, a key factor underlying the rapid development of
semiconductor technology has been a continuous imbalance between supply and
demand.

It is, however, also clear that no one has exactly been breaking Moore's
Law. Strictly speaking there is no such Law. Most discussions that quote
Moore's Law are historically inaccurate and extend its scope far beyond
available empirical evidence. Indeed, sociologically Moore's Law is a
fascinating case of how myths are manufactured in the modern society and
how such myths rapidly propagate into scientific articles, speeches of
leading industrialists, and government policy reports around the world.

It is therefore useful to revisit the evolution of Moore's Law. During its
lifetime, its interpretations have involved mainly technical and economic
considerations. The following discussion will therefore combine historical,
technical, and economic concepts and data.

The paper is organized as follows. In the next section, I revisit the
original formulation of the Moore's Law and describe its basic assumptions.
Section 3 discusses the revisions that Moore made to his original
formulation during the 1970s. Section 4 describes the extensions of Moore's
Law that became dominant in the 1980s and 1990s. Section 5 then evaluates
available evidence to see whether any of the proposed formulations of
Moore's Law can be justified. Its subsections review evidence on component
counts, microprocessor performance, increase in computing power, and
quality-adjusted cost of computing. Section 6 then briefly discusses
industrial dynamics that underlie technical development in semiconductors
and information processing, and points out some reasons why Moore's Law is
becoming increasingly misleading in forecasting future developments in
information processing technology. The paper concludes with some general
observations on the relation between technical, economic, and social
development.

 
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-- 
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R. A. Hettinga <mailto: rah at ibuc.com>
The Internet Bearer Underwriting Corporation <http://www.ibuc.com/>
44 Farquhar Street, Boston, MA 02131 USA
"... however it may deserve respect for its usefulness and antiquity,
[predicting the end of the world] has not been found agreeable to
experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire'