A storage device includes a nonvolatile memory device having a plurality of memory cells and a storage controller. Each memory cell is set to one of a plurality of memory cell states, wherein distinct subsets of the memory cell states are associated with one of a plurality of data sets. The storage controller accesses data stored in one of the memory cells in a first state, performs a multiplier-accumulator (MAC) operation on the data, and sets the one memory cell to a second state corresponding to a result of the MAC operation to perform an in-place update.