Method and systems are disclosed for increasing the number of ranks supported in a memory system. In one embodiment, a plurality of predefined subsets of memory chips on a memory module is selected. A chip select signal uniquely identifying the selected subset of memory chips is generated. The chip select signal is encoded as a multi-bit word having a bit width that is less than the number of predefined subsets of memory chips. Each bit of the encoded chip select signal is transmitted along a separate chip select line. The transmitted chip select signal is decoded to determine the identity of the selected subset of memory chips. The selected subset of memory chips identified by the decoded chip select signal are read or written.