I don't know the exact numbers but: I frequently used a VAX11/780. Its main components were two enclosures (CPU and Memory), each about a square meter in footprint and somewhere in the range of 1.6m high (IIRC). Both had their power delivered as 3x380V (i.e. European three-phase power) into the power supply part (the lower half to 2/3rds of those blocks) which turned it into rock solid 5V - and a LOAD of heat, which meant the room also needed some extra strong AC.

That thing was an 8MHz cpu with 8MB of RAM.