CSC/ECE 506 Spring 2012/1b ps

In 1965, Intel co-founder predicted that the number of transistors on a chip would double every 24 months. This was a rough predictive statement (not a true law of course) that has been claimed to be quite accurate in the decades since. This article explores different interpretations of Moore's law, whether it has failed to hold true during certain intervals of time, and, finally, whether it will continue to hold and, if so, for how long?

The rate of growth Moore predicted is truly staggering. The equation form of the law is: T(t)=T0 * 2^(t/2) where T0 represents the initial transistor count in the start year and Tn the transistor count in t years. This is somewhat lost on transistors so we'll switch to something everyone understands, money. If one could double his wealth every 24 months and started with $1, he would have $5,931,641 in 45 years!

But this is exactly what Intel claims it has done with their chips (and certainly their bottom line). To a large extent, the company has symbiotically harnessed and fueled the public awareness of Moore's law to their advantage as a marketing device, but it's still valuable to study the context of the prediction (the 60s and the advent of transistors) and the reasons Moore believed the prediction would hold and whether he was right.

If Moore was right, he wasn't right on the first try. His initial prediction was that transistor counts would double every year. In 1975 he revised this prediction to every two years (credit: http://news.cnet.com/Myths-of-Moores-Law/2010-1071_3-1014887.html). If we take 1971 and the Intel 4004 processor as our starting point, we see the following growth alongside the predicted growth and the variance and variance percentage next to each (credit for raw data: http://en.wikipedia.org/wiki/Transistor_count)

Processor Transistor count Year Predicted Value Variance Percent Error (Variance/Predicted Transistor Count) Intel 4004 2,300 1971 2,300 N/A N/A Intel 8008 3,500 1972 3,253 247 8% Motorola 6800 4,100 1974 6,505 -2,405 -37% Intel 8080 4,500 1974 6,505 -2,005 -31% RCA 1802 5,000 1974 6,505 -1,505 -23% MOS Technology 3,510 1975 9,200 -5,690 -62% Intel 8085 6,500 1976 13,011 -6,511 -50% Zilog Z80 8,500 1976 13,011 -4,511 -35% Motorola 6809 9,000 1978 26,022 -17,022 -65% Intel 8086 29,000 1978 26,022 2,978 11% Intel 8088 29,000 1979 36,800 -7,800 -21% Motorola 68000 68,000 1979 36,800 31,200 85% Intel 80186 55,000 1982 104,086 -49,086 -47% Intel 80286 134,000 1982 104,086 29,914 29% Intel 80386 275,000 1985 294,400 -19,400 -7% Intel 80486 1,180,000 1989 1,177,600 2,400 0% Pentium 3,100,000 1993 4,710,400 -1,610,400 -34% AMD K5 4,300,000 1996 13,323,023 -9,023,023 -68% Pentium II 7,500,000 1997 18,841,600 -11,341,600 -60% AMD K6 8,800,000 1997 18,841,600 -10,041,600 -53% Pentium III 9,500,000 1999 37,683,200 -28,183,200 -75% AMD K6-III 21,300,000 1999 37,683,200 -16,383,200 -43% AMD K7 22,000,000 1999 37,683,200 -15,683,200 -42% Pentium 4 42,000,000 2000 53,292,093 -11,292,093 -21% Barton 54,300,000 2003 150,732,800 -96,432,800 -64% AMD K8 105,900,000 2003 150,732,800 -44,832,800 -30% Itanium 2 220,000,000 2003 150,732,800 69,267,200 46% Itanium 2 with 9MB cache 592,000,000 2004 213,168,370 378,831,630 178% Cell 241,000,000 2006 426,336,740 -185,336,740 -43% Core 2 Duo 291,000,000 2006 426,336,740 -135,336,740 -32% Dual-Core Itanium 2 1,700,000,000 2006 426,336,740 1,273,663,260 299% AMD K10 463,000,000 2007 602,931,200 -139,931,200 -23% POWER6 789,000,000 2007 602,931,200 186,068,800 31% Atom 47,000,000 2008 852,673,480 -805,673,480 -94% AMD K10 758,000,000 2008 852,673,480 -94,673,480 -11% Core i7 (Quad) 731,000,000 2008 852,673,480 -121,673,480 -14% Six-Core Xeon 7400 1,900,000,000 2008 852,673,480 1,047,326,520 123% Six-Core Opteron 2400 904,000,000 2009 1,205,862,400 -301,862,400 -25% 16-Core SPARC T3 1,000,000,000 2010 1,705,346,960 -705,346,960 -41% Six-Core Core i7 (Gulftown) 1,170,000,000 2010 1,705,346,960 -535,346,960 -31% 8-core POWER7 1,200,000,000 2010 1,705,346,960 -505,346,960 -30% Quad-core z196[3] 1,400,000,000 2010 1,705,346,960 -305,346,960 -18% Quad-Core Itanium Tukwila 2,000,000,000 2010 1,705,346,960 294,653,040 17% 8-Core Xeon Nehalem-EX 2,300,000,000 2010 1,705,346,960 594,653,040 35% Six-Core Core i7 (Sandy Bridge-E)2,270,000,000 2011 2,411,724,800 -141,724,800 -6% 10-Core Xeon Westmere-EX 2,600,000,000 2011 2,411,724,800 188,275,200 8%

So it's quite clear that the "law" is not to be taken too literally. It's a general marker for what to expect in upcoming years. One sees actually that the number jump to catch up (by 2011, the variance is only %8 with the 10-Core Xeon chip). The Dual Core Itanium also lurches forward nearly %300.