A memory system includes a memory array having a plurality of memory cells; and a controller coupled to the memory array, the controller configured to: designate a storage mode for a target set of memory cells based on valid data in a source block, wherein the target set of memory cells are configured with a capacity to store up to a maximum number of bits per cell, and the storage mode is for dynamically configuring the target set of memory cells in as cache memory that stores a number of bits less per cell than the corresponding maximum capacity.