A computer system comprises a computer that includes a plurality of CPU sockets including one or more CPU cores, a crossbar switch, and a memory controller each, and memories connected under the respective plurality of CPU sockets, the plurality of CPU sockets being connected to each other. When all the CPU cores in a CPU socket enter a power saving state and a total amount of memory use falls below a predetermined threshold, the computer relocates contents of the memory connected under the CPU socket to a memory under another CPU socket, thereby eliminating an access to the memory connected under the CPU socket and bringing a whole of the CPU socket into the power saving state.