>I'm curious just how true it is that Moore's law is starting to approach physical limitations.
Well, Moore's "Law" in the narrow sense has been, to a large degree, about CMOS process scaling and that's clearly running into physical limits.
There are other levers to get better economical performance--some of which come at the cost of extra work in software. For certain workloads, GPUs and TPUs have been an important work around. There almost certainly are further optimizations involving stacking and interconnects. Probably other application-tailored designs (which then have to have software tailored for them individually).
But CMOS scaling has been such a powerful lever that there's legitimate concern that it may not be possible to replicate that kind of advance using other techniques.
Well, Moore's "Law" in the narrow sense has been, to a large degree, about CMOS process scaling and that's clearly running into physical limits.
There are other levers to get better economical performance--some of which come at the cost of extra work in software. For certain workloads, GPUs and TPUs have been an important work around. There almost certainly are further optimizations involving stacking and interconnects. Probably other application-tailored designs (which then have to have software tailored for them individually).
But CMOS scaling has been such a powerful lever that there's legitimate concern that it may not be possible to replicate that kind of advance using other techniques.