Quote from: Tangled-Universe on January 03, 2020, 11:45:52 AMMore PCI lanes and greater max RAM capacity, for instance.
Thaaat's not really a design difference, that's allowance because of power...
Maybe actually look up the CPU architecture. You said they're quite different when they're essentially the same in different form factors, one having of course a lot more core-head room for I/O, PCI lanes, and RAM, but this is inherent to any CPU and isn't a "difference" beyond performance. Architecture is CPU differences, which would also encompass CPU compatibility.
Usually when people talk about CPU differences, it's architecture. Like Zen 1 vs Zen 2, or Zen 2 vs Ice Lake or something of that, which actually compares differences in CPU architecture and functionality.