A multicore processor system includes one or more client carrying out parallel processing of tasks by means of processor cores and a server assisting the client to carry out the parallel processing via a communication network. Task information containing the minimum number of required cores indicating the number of processor cores required to carry out processes of the tasks and core information containing operation setup information indicating operation setup content of the processor cores are stored in the server. The server determines whether the task is allocated to the plurality of processor cores or not in accordance with the task information and the core information. The server updates the core information in accordance with a determination result to transmit the updated core information to the client. The client carries out the parallel processing by means of the processor cores in accordance with the received core information.