A power management method includes monitoring a status of an external interface of external interfaces between the fabric network and at least one host, and a status of an internal interface of internal interfaces between the fabric network and at least one storage device of a plurality of storage devices. The power management method further includes calculating aggregate information of bandwidths of internal interfaces of the plurality of storage devices based on the monitoring, the at least one storage device connected to the at least one host. The method further includes adjusting the bandwidths of the internal interfaces such that the aggregate information of the bandwidths of the internal interfaces is within a threshold range, the threshold range based on a bandwidth of the external interface connected to the at least one host.