> No, chiplets were called MCMs. IBM and others as you noted had chip(lets) in MCMs that were not "fully-functioning" by themselves.
I don't follow; you seem to be using "chiplet" to directly mean a multi-chip module, whereas I consider "chiplet" to be a component of a multi-chip module. An assembly of multiple chiplets would not itself be "a chiplet", but a multi-chip module. This is also why I don't follow why the term "chiplet" would replace the term "multi-chip module", because to me, a multi-chip module is not even a chiplet, it's only built with chiplets.
Are chiplets ever more than a single die? Conversely, are there multi-chip modules of only a single die? At least one of these must be true for "chiplet" and "multi-chip module" even to overlap.
Sorry I flubbed that -- I meant what are now called chiplets interconnected and packaged together used to be called MCMs. A chip was always a single piece of silicon (aka die), so chiplets used to just be called chips. There was never any rule that chips in an MCM were "standalone" or functional by themselves like some seem to be saying, in fact earlier computers used multiple chips for subsystems of a single CPU (https://en.wikipedia.org/wiki/POWER2 this thing had individual chips for IFU, LSU, ALU, FPU, and D$). There was never any rule that MCMs were not low latency or high bandwidth or must have a particular type of interconnect or packaging substrate.
Advances in technology and changing economics always shifts things around so maybe chiplets are viable for different things or will make sense for smaller production runs etc., but that doesn't make them fundamentally different that would make them not classified as an MCM like the article seems to suggest. It literally is just the same thing as it always was, multiple chips packaged up together with something that is not a standard PCB but is generally more specialized and higher performing.