Term DIMM has to do with the actual mechanical connector, not with data bus width. SIMM modules have pads on opposite sides of connector connected together, DIM

Term DIMM has to do with the actual mechanical connector, not with data bus width. SIMM modules have pads on opposite sides of connector connected together, DIMM ones do not. There is even JEDEC specification for DIMMs with 32-bit wide data bus (Such DIMM was used in Corel's NetWinder for instance). And as for parallel vs. serial, essentially whole second page of the articles is about issue that is mostly specific to synchronous parallel interfaces. Multilane PCI-E neatly sidesteps such issues by using what essentially amounts to multiple independent serial links that are bonded together. But having serial interface to RAM chip greatly increases the complexity of the RAM chip (SDRAM protocol looks at the first glance as something that is very hard to implement in RAM chip, but in comparison with interfaces like PCI-E it's trivial state machine).