A bus system includes a plurality of stubs; a plurality of connectors, each of which is serially coupled between a corresponding one of the stubs and a corresponding one of memory modules; a plurality of first serial loads, each of which is serially coupled to a corresponding one of the connectors; and a plurality of second serial loads, each of which is serially coupled to characteristic impedance of a transmission line of a corresponding one of the stubs, wherein the first and the second serial loads are determined to be impedance matched at each transmission line terminal of the stubs.