Nice to see an article address what Moore actually said (transistor count doubles every 24 months) and not what people often thinks Moore said (performance doubles every 24 months).
It started out as every 12 months in the original 1965 article which lasted for about a decade before being updated to 18 months, and relatively recently people started talking 24 months.
In the early 1980s there was a time it seemed to hang in the air because all the clock rates in a micro were synchronized to the video scan. Steve Jobs had no idea the Apple ][ was going to last as long as it did so they came out with the the failed /// and the 128k Max that was really just an awesome demo.
It wasn’t until the mid 1980s that PC compatibles reached a place where you could buy a new computer that was exponentially better than the computer you bought 2 years ago but that was gone around 2005. Until then the smaller transistors were really faster and consumed less power but since then you mostly have more of them and moderate improvements in power consumption.
In the beginning, everything good correlated with more transistors: decreased pitch led to lower power per transistor, faster clock frequency (implying faster RAM), more RAM, and lower cost per transistor. In the decades since pretty much everything but "number of transistors" has fallen off. Pitch doesn't mean pitch, clock speeds are a function of cooling, cost is going up.
One thing that has correlated well with Moore's Law still is exponential cost to open a new fab, and fewer companies chasing the latest node. As Moore's Law slows, and possibly eventually ends, the end is going to be caused by economics, not just physics.
Yeah, to some extent- how much I'm not sure- Moore's Law became a self-fulfilling prophecy. Because everyone knew that transistor count was about to double, everyone- including the Wall Street investors- agreed that you needed to spend all that money to build that new fab, because if you didn't you can be damn sure your competition would. So the semiconductor industry "was allowed" by investors to continue making enormous investments in the next generation of fabs. If there was some similar law for, say, rockets, could we have had that sort of progression in space travel instead?
No, because the economics are different. To put some things in context:
- Cost of the Saturn V development program: $6.417bn then / $35.4bn in 2020 dollars
- Cost of TSMC's Arizona fab: $12bn now
- The Saturn V program launched a handful of humans into space for $0.185bn then / $1.23bn now per launch.
TSMC's fab may cost a lot, but it produces a very large number of chips and, most importantly, it's reusable. The most density- and performance-sensitive applications use the newest fabs first, but the fabs are not thrown out immediately after a newer process is developed. Instead, the older fabs start making cheaper chips that don't need leading-edge performance. All of that up-front cost is amortized over a decade of continuous use.
If investors had poured money into rockets instead of chip fabs, we wouldn't have had everyone going to space. The investors would have just lost their shirt. Space has inherent costs we can't engineer around (e.g. fuel) and getting there is primarily a scientific endeavor rather than a consumer good. Keep in mind, there's nowhere to go[0] in space once you get there, except back to Earth.
Meanwhile, chips are something everyone needs now, and owning a fab is still a profitable venture even when the R&D costs go up - at least, for as long as the manufacturing technology works and people are willing to pay a premium for better chips. It's not purely an R&D arms race.
[0] I am leaving the possibility of terraforming Mars out of this, as that has enormous problems on its own.
Cost per device might have flattened at the leading edge (where fabbing processes are increasingly customized, so skyrocketing costs are to be expected) but the trailing edge is seeing more improvement, AIUI.
>and not what people often thinks Moore said (performance doubles every 24 months).
Performance double every 24 months isn't the modern take anymore. In the past 3 years all major PR has twisted the word "Moore's Law" to just meant transistor improvement.
It's not even that, and it never really has been. Anyone talking about performance was misrepresenting it. The prediction was that the density with which you're at the point of minimum-cost-per-transistor would double every year. It was also originally a prediction going out 10 years to 1975.
The more transistors you put on a chip, the less expensive each transistor is, but the higher the risk of defects, so there's always an optimum amount as your fabrication processes improve.
> The complexity for minimum component costs has increased at a rate of roughly a factor of two per year (see graph on next page). Certainly over the short term this rate can be expected to continue, if not to increase. Over the longer term, the rate of increase is a bit more uncertain, although there is no reason to believe it will not remain nearly constant for at least 10 years. That means by 1975, the number of components per integrated circuit for minimum cost
will be 65,000.
> I believe that such a large circuit can be built on a single wafer.