1. A method comprising: receiving data to be written to a NAND array in a controller; and writing the data to the NAND array, the NAND array comprising both type A NAND cells and type B NAND cells, wherein the type A NAND cells and the type B NAND cells have at least one structural difference, wherein the type A NAND cells and the type B NAND cells are of a same configuration, wherein the same configuration is either a single level cell configuration or a multilevel cell configuration.