A Smaller-sized Small Form-factor PC Mobo
As with MicroATX boards, small form-factor PC motherboards come with nearly every conceivable port and feature. Users do need these, as for every expansion an internal slot is taken up - and these are in notoriously short supply. External devices represent an alternative to expansions.
Still, not everything can be installed or expanded externally. This applies to graphics, LAN, USB, FireWire and serial ports, in addition to memory of course. External USB solutions are already being offered for audio. There are already a wide range of alternatives for disk and hard drives.
Typical small form-factor PC motherboard with PCI Express and two DIMM memory sockets.