This comment is the first time I've seen the why of this number explained, thanks. Like, makes sense, it must be tied to some relative scale that's vaguely comparable across companies otherwise it's just kind of silly. I obviously can understand the 'marketing speak' argument but past a certain point it becomes literally nonsense if people are just using arbitrary numbers.
One extra complicating factor is that each process node will have several different transistor libraries that make different tradeoffs between density and power/frequency. So a smartphone SoC will tend to have a higher MT/mm^2 number than a server CPU or GPU.
Yeah, the difference is more or less a factor of 3. The node gives you a smallest transistor size but making some transistors bigger than others lets you reach higher frequencies.
