A data processing system includes data processing devices each including a computing memory and configured to perform a task; one or more host devices connected to the data processing devices, and each configured to: select one or more of the data processing devices based on meta information including a size of a memory, and sizes of the computing memories of the respective data processing devices, and request the selected processing devices to perform a first task; a network switch configured to connect the one or more host devices to the data processing devices; and a network manager in the network switch and configured to: collect free memories of the respective data processing devices based on the meta information and the sizes of the computing memories of the respective data processing devices, and control the one or more host devices to use some of the free memories.