An extended-height DIMM for use in a memory system having slots designed to receive DIMMs that comply with a JEDEC standard that specifies a maximum height for the DIMM and a maximum number of devices allowed to reside on the DIMM. The DIMM comprises a PCB having an edge connector designed to mate with a memory system slot and a height which is greater than the maximum height specified in the applicable standard, a plurality of memory devices which exceeds the maximum number of devices specified in the applicable standard, and a memory buffer which operates as an interface between a host controller's data and command/address busses and the memory devices. This arrangement enables the extended-height DIMM to provide greater memory capacity than would a DIMM which complies with the maximum height and maximum number of devices limits.