Patent ID: 8751750

Claim:
A cache device which temporarily stores data transmitted and received between a user terminal and a storage device, the cache device comprising: a data recorder which records cache data and buffer data at a storing part, wherein the cache data comprises data which is to be stored at the storage device, and wherein the buffer data comprises data which is to be written to the storage device; a deleted cache determining device which determines the cache data which is to be deleted from the storing part if a sum of a data amount of the data which is recorded at the storing part and a data amount of the cache data which is stored at the storing part and a data amount of the buffer data which is stored at the storing part is equal to or more than a predetermined threshold; a cache deleting device which deletes, from the storing part, the cache data which is determined by the deleted cache determining device; a buffer transmitter which transmits the buffer data which is stored at the storing part to the storage device; a buffer deleting device which deletes, from the storing part, the buffer data which is transmitted by the buffer transmitter; and a transmission rate determining device which determines a transmission rate of the buffer data such that the larger the cross traffic number in a network between the storage device and the cache device, the slower the transmission rate; wherein the buffer transmitter transmits the buffer data to the storage device at the transmission rate which is determined by the transmission rate determining device.