Storing device and method for storing data thereof

[0001] The embodiment of the invention discloses a kind of storing device and store the method for data, storing device comprises cache controller, buffer memory and persistent storage medium, and buffer memory comprises multiple data block. Method comprises cache controller according to the number of times AC writing access of each data block in multiple data block and the quantity AN acquisition brush index writing the address that access is accessed. Data in part data block in multiple data block are stored into described persistent storage medium. Wherein, the position of the brush index of each data block in part data block in the brush index sequence from big to small of multiple data block is all greater than queue thresholds. The embodiment of the present invention by low for brush index, write amplify bigger data block wouldn't be stored into persistent storage medium. It is polymerized in cache, promotes brush index. After the brush index of data block promotes, then data block being stored in persistent storage medium, what decrease data writes amplification.