1. A system including a master memory controller, a plurality of memory modules arranged into N rows by M columns of memory modules coupled to the master memory controller to form a two-dimensional memory array of Z memory slices over the M columns of memory modules, wherein each memory module includes a plurality of read-writeable non-volatile memory devices in a plurality of memory slices to form a portion of the two-dimensional memory array of Z memory slices, wherein each of the plurality of memory slices in each memory module includes a slave memory controller coupled to and between one or more of the plurality of read-writeable non-volatile memory devices and the master memory controller; and wherein the master memory controller forms a compound memory request comprising a plurality of slice requests that is partitioned into a slice request for each respective memory slice of the Z memory slices over the M columns of memory modules.