[kimixa]

Currently the performance and power benefits of having tightly packaged RAM are taken full advantage of by the M1 family. A less tightly coupled memory system will likely have significant performance implications. There's a reason why all GDDR memory for GPUs is soldered, as there's signaling issues caused by things like longer traces and the electrical behavior of the sockets themselves.

People also seem often to forget that interconnects are a significant amount of modern power budgets - look at the Epic IO die often using more than the cores in many workloads. It may be the the M1 family looks less attractive when you actually have to add these requirements.

Perhaps there's some possibility of having both a tightly-coupled RAM package and also have an extensible memory system - though that has significant management complexity if you try to treat it like a cache, or likely needs app support if it's some NUMA system where they're mapped separately. But possible, at "just" the cost of the extra memory controller.