In one embodiment, a method includes receiving from a memory controller, a request to access memory stored at memory modules, the request directed to one of a plurality of logical ranks, mapping at a rank aggregator, the logical rank to one of a plurality of physical ranks at the memory modules, and forwarding the request to one of the memory modules according to the mapping. Two or more of the memory modules are combined to represent the number of logical ranks at the memory controller such that there is a one-to-one mapping between the logical ranks and the physical ranks. An apparatus for rank aggregation is also disclosed.