1. A method comprising: receiving from a memory controller, a request to access memory stored at memory modules, said request directed to one of a plurality of logical ranks; mapping at a rank aggregator, said logical rank to one of a plurality of physical ranks at the memory modules, wherein two or more of the memory modules are combined to represent a number of said logical ranks at the memory controller such that there is a one-to-one mapping between said logical ranks and said physical ranks; and forwarding said request to one of the memory modules according to said mapping.