Online Computer Terms Dictionary - M

Moore's Law

<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 clock rates.

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.

http://www.intel.com/intel/museum/25anniv/html/hof/moore.htm.

Intel Microprocessor Quick Reference Guide.

"Birth of a Chip", Linley Gwennap, Byte, Dec 1996. See also March 1997 "inbox".

Chronology of Events in the History of Microcomputers, Ken Polsson.