Patent ID: 8134798

Claim:
A disk drive comprising: (a) a plurality of disk surfaces, wherein each disk surface comprises a plurality of data tracks, and each data track comprises a plurality of data sectors; and (b) control circuitry operable to: receive a read command from a host; read data from first and second data sectors on first and second disk surfaces, respectively, in response to the read command, wherein: the first data sector stores data at a first data rate, and the second data sector stores data at a second data rate substantially less than the first data rate; transfer the data to the host at a substantially constant average transfer rate, wherein the substantially constant average transfer rate is a transfer rate between the first data rate and the second data rate; read the data from a first plurality of data sectors in a first plurality of data tracks on the first disk surface and from a second plurality of data sectors in a second plurality of data tracks on the second disk surface; and perform a first seek operation to seek a head from a current data track to a next data track on the first disk surface, and a second seek operation to seek the head from a current data track to a next data track on the second disk surface; wherein: a first rotational delay occurs after the first seek operation and prior to the control circuitry reading data from a data sector in the next data track on the first disk surface; a second rotational delay occurs after the second seek operation and prior to the control circuitry reading data from a data sector in the next data track on the second disk surface; and the first rotational delay is substantially greater than the second rotational delay so that the control circuitry transfers the data to the host at the substantially constant average transfer rate.