The final challenge will be cost: With every iteration, costs increase dramatically. At some point, it simply ceases to make sense to scale down transistors any further.
Many semiconductor manufacturers have folded, dropped out, or merged over the years due to costs putting development of the next node out of their reach. If the remaining 3 drop out of the race, they will be following the same pattern as many before.
Maybe it will make sense for mobile SoCs or some other energy constrained applications which benefit from lower power draw of smaller process node chips. But power efficiency can outweigh lower absolute performance only to some degree.
I'm not talking about the marginal cost to make the device, I'm talking about the R&D and capital expenditure to develop and build the machines for the next node.
You can be reductive and say it always boils down to competition, but then you would also say that ultimately shrinking will end when it can no longer compete with mature nodes. Competition in both cases. So I'm not sure what exactly that's getting at.
> If it soon goes up significantly, it will stop to make economic sense to increase transistor density any further. Why pay the same amount of money for a less powerful chip?
That's not strictly true, performance of a transistor still has value. Companies like Apple pay premiums to get in early on leading edge nodes, more per device than the mature nodes they move from.
> That's not strictly true, performance of a transistor still has value. Companies like Apple pay premiums to get in early on leading edge nodes, more per device than the mature nodes they move from.
Apple can't increase the price of their product arbitrarily. So if the price per performance increases, the new iPhone would be slower than the old one. Maybe people will still buy it if it has better power efficiency, but that is a trade-off which has its limits.
Not arbitrarily, but IIRC Apple's profit margin on iPhones is over 100% - the iPhone 14 Pro max is supposed to have a BoM cost of ~470 $ and retails for well over 1000$. That means Apple can both afford the high upfront premium/R&D cost of going to a smaller node and to eat up higher SoC costs and yet still have a profit per unit that would lead most other companies' CFOs to drool.
On top of that, even if the economics should not work out for mobile... a fully spec'd out M2 Ultra Mac Pro runs at ~14.000$, Intel ones IIRC could reach 50.000$. The crowd that pays such absurd prices has zero problems paying a grand or two more for higher performance.
No, why? Lots of foundries out there that don't compete on leading edge nodes.
> Apple can't increase the price of their product arbitrarily. So if the price per performance increases, the new iPhone would be slower than the old one. Maybe people will still buy it if it has better power efficiency, but that is a trade-off which has its limits.
That doesn't address what I said -- that price per transistor is not the single limiting factor. I never said any performance increase is worth infinite value.
The discussion was about Moore's law ("scaling down"), which is only about the leading edge.
No, the point was that the leading edge will stop advancing when it can no longer compete economically with companies that sell mature nodes. Which is obvious, but I was just being similarly reductive.
> The point is that they will stop scaling chips before technical limits are reached.
Sure, like most commercial ventures, cost becomes prohibitive at some point and overtakes benefits. As it always has been.
The "mature node" here will just be the one before the first node that doesn't make economic sense anymore. And this will be from a leading edge company, most likely TSMC. Say, if 2nm is too expensive compared to 3nm, then TSMC will stick with 3nm.