A memory system includes a plurality of memory dies and a controller coupled with the plurality of memory dies via a plurality of channels. The controller is configured to perform a correlation operation on at least some read requests among a plurality of read requests inputted from an external device so that the plurality of memory dies outputs plural pieces of data corresponding to the plurality of read requests via the plurality of channels in an interleaving way. The controller is configured to determine when to perform the correlation operation based on the number of the plurality of read requests.