Couple things, why are you completely dismissing Samsung 5nm? Not saying it's likely, or ideal, but certainly possible unless I am missing something. It makes more sense than 8nm, it's just not as good as 4N.
N64 was actually very capable, and programmers have actually been able to recompile Mario 64 to be a 60fps game on native hardware. Developers just didn't have the experience at that point to really squeeze efficiently with the N64 hardware.
I’m not actually completely dismissing it at all, though admittedly my wording may give that impression. I think it ultimately has to be discussed given Nvidia having a history with Samsung. As mentioned, I think it’s still unlikely, especially after what others here have talked previously regarding yield rates and such. But that doesn’t discount it completely either. We’ve also talked previously that maybe if Samsung were desperate for someone to use their 5nm process, and were going to give Nintendo/Nvidia a very good deal, it could still be possible.
Won’t be as efficient, but has Nintendo ever gone with the most efficient nodes in their chips?
As far as your other question, someone else brought up concerning microcode, which wasn’t made available to most developers outside of Nintendo until much later. Gunpei himself even admitted that the system was meant for peak performance rather than sustained performance.
That does not imply the N64 cannot do sustainable performance as you mentioned though. Kaze Emanuar worked wonders in getting Mario 64 to work at 3x the frame rate, something that most would consider to be impossible. And then you have James Lambert who recently got Portal to run on native hardware, plus his work in getting megatextures to work.
Like you said, developers and other programmers are finding new and creative solutions to work around limitations.
How this ties into Switch 2 is I think Nintendo, like what they did for Switch 1, is lay on the side of caution, and provide an experience that relies more on sustainable performance over the long term, which falls right in line with what Gunpei said about the N64. Whether or not the GCN, Wii, or Wii U truly followed that though is a different discussion, though could be talked about later on.
I just think we can find many clues into Nintendo’s plans just by reading what they’ve talked about over the last 30 years. We can find a similar realm of thinking with Nintendo’s philosophy of withered technology with lateral thinking. That, and withered (or weathered could be another term) being abundant, well understood, and cheap.
So I guess following that own logic, what chip node process follows those three things? Does TSMC 4N follow that? How about Samsung 5nm? Or TSMC 7N? There are a few possibilities here.