The stackable motherboard 10 of the first embodiment includes: a circuit board 19 having a first side 14 and a second side 17 opposite the first side 14, a processor 16 mounted on the circuit board 19, a first peripheral interconnect 18, and a second peripheral interconnect 90. The stackable motherboard 10 also preferably includes: a first motherboard interconnect 99 mounted on the first side 14 of the circuit board 19 and adapted to communicate data between the processor 16 and a first auxiliary motherboard, and a second motherboard interconnect 94 mounted on the second side 17 of the circuit board 19 and adapted to communicate data between the processor 16 and a second auxiliary motherboard.