Patent ID: 7231495

Claim:
A secondary storage device capable of speculatively reading data, the secondary storage device comprising: reading means for reading a first datum from a storage medium; determining means for determining a probability of the secondary storage device receiving a read request for a second datum stored on the storage medium, the second datum being logically related to the first datum, and the determining means also, if the probability is above a pre-determined probability value, determining a cost to speculatively read the second datum, the cost being based on a position of a read/write head, relative to the second datum's physical location on the fixed medium, when the read/write head is reading the first datum; storing means for, if the cost to speculatively read the second datum is below a pre-determined cost value, reading the second datum without a request being received from outside the secondary storage device for the second datum, the storing means then storing the second datum in a secondary storage device cache; and producing means for producing the second datum from the secondary storage device cache if the secondary storage device receives a later request for the second datum.