A memory system includes a plurality of memory devices on a printed circuit board, each of the memory devices including a plurality of external pads; a plurality of connection terminals formed on the printed circuit board, and electrically connected to respective ones of the external pads; and a plurality of signal lines formed on the printed circuit board to connect the connection terminals with the external pads, each of the signal lines between a corresponding connection terminal and a corresponding external pad and having a length. The plurality of memory devices are arranged at different distances from the plurality of connection terminals, and each signal line that connects a connection terminal to an external pad of a memory device either is connected to or does not connect a stub resistor depending on a length of the line.