A multiprocessor system is provided, comprising a baseboard, for arranging peripheral equipments; and a plurality of processor modules, each equipped with a processor and a board-to-board connector; wherein the plurality of processor modules are stacked up, with board-to-board connectors being electrically connected between the processor modules and between the processor modules and the baseboard; the processors communicate with the peripheral equipments in accordance with a specific bus specification; and the operations of the plurality of processor modules are coordinated by routes provided between the processor modules and between the processor modules and the baseboard.