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Computing (FOLDOC) dictionary
Moore's Law
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architecture /morz law/ The observation, made in 1965 by
Intel co-founder Gordon Moore while preparing a speech,
that each new memory integrated circuit contained roughly
twice as much capacity as its predecessor, and each chip was
released within 18-24 months of the previous chip. If this
trend continued, he reasoned, computing power would rise
exponentially with time.
Moore's observation still holds in 1997 and is the basis for
many performance forecasts. In 24 years the number of
transistors on processor chips has increased by a factor of
almost 2400, from 2300 on the Intel 4004 in 1971 to 5.5
million on the Pentium Pro in 1995 (doubling roughly every
two years).
Date Chip Transistors MIPS clock/MHz
Nov 1971 4004 2300 0.06 0.108
Apr 1974 8080 6000 0.64 2
Jun 1978 8086 29000 0.75 10
Feb 1982 80286 134000 2.66 12
Oct 1985 386DX 275000 5 16
Apr 1989 80486 1200000 20 25
Mar 1993 Pentium 3100000 112 66
Nov 1995 Pentium Pro 5500000 428 200
Moore's Law has been (mis)interpreted to mean many things over
the years. In particular, microprocessor performance has
increased faster than the number of transistors per chip. The
number of MIPS has, on average, doubled every 1.8 years for
the past 25 years, or every 1.6 years for the last 10 years.
While more recent processors have had wider data paths,
which would correspond to an increase in transistor count,
their performance has also increased due to increased clockrates.
Chip density in transistors per unit area has increased less
quickly - a factor of only 146 between the 4004 (12 mm^2) and
the Pentium Pro (196 mm^2) (doubling every 3.3 years).
Feature size has decreased from 10 to 0.35 microns which
would give over 800 times as many transistors per unit.
However, the automatic layout required to cope with the
increased complexity is less efficient than the hand layout
used for early processors.