A server system includes a rack, a power supply module, a switch, and a plurality of servers. The rack can be divided into a plurality of rack units. The rack units are parallel to each other and vertically arranged. The power supply module and the switch are disposed in close proximity to each other in at least one of the rack units. The power supply is adjacent to the rear side of the rack. The switch is adjacent to the front side of the rack. Each of the servers is disposed in one of the other rack units and electrically connected to the power supply module and the switch.