In one embodiment of the invention, a server is disclosed including a main printed circuit board; a plurality of processors mounted to the main printed circuit board; and a memory system accessible to the plurality of processors. The memory system includes a plurality of expansion sockets mounted to the printed circuit board, and a plurality of server memory cards removeably plugged into the plurality of expansion sockets. Each server memory card includes a master controller, a plurality of slave controllers, and a plurality of replaceable daughter-memory-cards with read-writeable non-volatile memory.