…twice the number of components won’t appear on the next IC chip (Part 1 of 4)
Gordon Moore always calls it “so-called Moore’s Law” when discussing his eponymous observation about IC scaling trends, and he has always acknowledged that it’s no more and no less than a marketing tool used to inform an ecosystem of downstream chip-users of price:performance improvements planned. The original observation published in 1965 and updated in 1975 established that the number of functional circuit components—including transistors, diodes, and any passive components—on a single IC chip doubled periodically.
- Die size increase,
- Dimension decrease (a.k.a. “shrink”),
- Device and Circuit design (a.k.a. “cleverness”).
Note that Moore never said anything about cost, speed, power-consumption, or reliability. It was left to the IC sales guys to inform that lithographic R&D meant that the next generation chips would actually be smaller and cost less, and most importantly the ability to maintain Dennard Scaling with power-reduction/transistor rules meant that each chip reliably consumed less power. This was the glory era when each new chip generation provided it all: more components, faster speed, and cheaper price.
Five years ago, Gordon Moore and Jay Last provided an insightful review of the founding of the IC industry at the Computer History Museum, which I covered in an independent blog posting (http://www.betasights.net/wordpress/?p=758). As well summarized in the “Transistor Count” entry at Wikipedia (https://en.wikipedia.org/wiki/Transistor_count) by 1975 the industry was working on designs with 10k transistors, and 100k by 1982, and 1 million by 1989. Incredibly, the trend continued to 1 billion transistors on a chip in production in 2010.
In my interview with Gordon Moore published in the July 1997 issue of Solid State Technology, he emphasized two points: the atomic limits of IC manufacturing, and the fact that when we start to reach atomic limits we’ll be able to put 1 billion circuit elements into a square centimeter of silicon. However, henceforth we will no longer get it all with the next generation chips, and will only be able to choose one from the glory list that used to be a package deal (pun intended): more, faster, cheaper. IC innovation will certainly continue, but it will not come through smaller and faster and cheaper circuit elements. Moore’s accurate prediction of gigascale circuitry on cheap chips explicitly sets the stage for the next 50 years of innovation in IC manufacturing…we’ve only begun to play with billions of transistors.
Make no mistake, everyone wishes that Moore’s Law was still alive and well. IC fabs most of all, but everyone from economists and politicians promising exponential growth (http://www.foreignpolicy.com/articles/2010/10/11/opening_gambit_moores_flaw) to futurists selling absurd fantasies of benevolent nanobots (http://www.singularity.org) deeply wish that Moore’s Law would continue. Sadly, no exponential in the real world can go on forever, and we make mistakes when we blindly ignore changing conditions behind an exponential trend.
More than ever before, people with little understanding of what Gordon Moore said let alone what he meant try to discuss the ramifications of an eventual end to Moore’s Law. In particular, people who have never worked in a semiconductor fab nor designed a commercial IC love extrapolating prior trend-lines forward without an understanding of how we got here nor a clue about the real atomic and economic limits of IC production.
Some analyses ignore the realities of manufacturing process control (http://www.mooreslaw.org/) while others revel in extrapolations based on mathematical abstractions and economic theories (http://www.ebnonline.com/author.asp?section_id=3315&doc_id=273652), and such work can be so bad that it is “not even wrong”.
Imminent posts in this blog series will discuss:
Moore’s Law is Dead – (Part 2) When we reach economic limits,
Moore’s Law is Dead – (Part 3) Where we reach atomic limits,
Moore’s Law is Dead – (Part 4) Why we say long live “Moore’s Law”!
—E.K.