Data storage device having multiple heads traveling in opposite directions for capacity and throughput optimization

Abstract

Methods and systems for improving the storage capacity and data throughput of a digital mass storage device. The novel optimizations can be applied to a disk drive, either a hard disk drive or a disk drive having removable media, such as magnetic and optical disk drive technologies. The present invention provides at least two disk drive heads for reading and writing information from two different spinning media surfaces, e.g., platters or disks. If the disk is a read-only device, then the heads only perform the read function. A constant angular velocity drive mechanism is used meaning the rotational speed of the media is constant regardless of the head's position with respect to the media. In operation, during a media transfer, the first head accesses data by starting at the outside regions (“high track rates”) of the disk media and traversing inward towards the inner regions (“low track rates”). The second head, moving the opposite direction but in synchronization with the first head, starts accessing data in the inner regions of its disk media and traverses towards the outer regions. A data file is portioned and its portions are accessed using both heads combined to provide a uniform and high data throughput. The sectors are specially mapped and the data is interleaved to provide a maximum throughput. Capacity is increased because much, if not all, of the inner regions of the disk media are used in the present invention while still maintaining a high and uniform data throughput.