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 | |
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 6502 | 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.
The following chart shows the actual and predicted transistor counts: