A data storage apparatus includes a non-volatile hard disk drive platter, a coupling interface for removably receiving a non-volatile solid state device operable as a cache. The data storage apparatus also includes a communication line functionally connected to the hard disk drive platter and the coupling interface and a storage controller are connected to the communication line to control operations of the hard disk drive platter and the solid state device, in which the storage controller is to determine whether the solid state device is coupled to the coupling interface and to modify operations of the hard disk drive platter based upon whether the solid state device is coupled to the coupling interface.