An actuator arm assembly of a hard disk drive. In various embodiments, the method may include identifying successively one or more critical time intervals, and scheduling andor organizing task execution for each of the one or more identified critical time intervals. A power line supply select at each row selectively increases cell supply voltage to a full supply voltage when the row is selected. Also, one time use of the MFD can be enabled by entering credit or debit card information. The second portion extends in a direction substantially perpendicular to the medium facing surface.