A neural processing device includes a first memory configured to store universal data, a second memory distinguished from the first memory and having a capacity less than that of the first memory, a bandwidth control path configured to reconfigure a memory bandwidth for memory clients to use one of the first memory and the second memory based on a control signal, and a control logic configured to calculate a target capacity for data of a target client of the memory clients determined based on a layer configuration of an artificial neural network, and generate the control signal to store the data of the target client in the second memory based on a result of comparing the target capacity and the capacity of the second memory.