Patent ID: 6987630

Claim:
A method for determining a media thermal decay rate comprising the steps of: providing a disk drive having a disk surface and a head associated with the disk surface; predetermining a decay measurement duration; writing reference patterns in a plurality of reference sectors on a test track; after at least two decades of time longer than the predetermined decay measurement duration have passed since writing the reference patterns in the plurality of reference sectors, writing sector-under-test patterns in a plurality of sectors-under-test, wherein the sectors-under-test and the reference sectors are written in data sectors and alternate with one another about at least a portion of the test track; measuring mean square error for the reference sectors; averaging the mean square error for the reference sectors; measuring mean square error for the sectors-under-test; averaging the mean square error for the sectors-under-test; using the averaged mean square error for the reference sectors and the averaged mean square error for the sectors-under-test to calculate the media thermal decay rate.