Methods and apparatus are disclosed for managing the storage of dynamic neural network data within bit-addressable memory devices, such phase change memory (PCM) arrays or other storage class memory (SCM) arrays. In some examples, a storage controller determines an expected amount of change within data to be updated. If the amount is below a threshold, an In-place Write is performed using bit-addressable writes via individual SET and RESET pulses. Otherwise, a modify version of an In-place Write is performed where a SET pulse is applied to preset a portion of memory to a SET state so that individual bit-addressable writes then may be performed using only RESET pulses to encode the updated data. In other examples, a storage controller separately manages static and dynamic neural network data by storing the static data in a NAND-based memory array and instead storing the dynamic data in a SCM array.