An aspect of the invention can be regarded as a disk drive that includes a
disk drive base and a spindle motor hub rotatably coupled to the disk
drive base. The disk drive further includes a first disk disposed about
the spindle motor hub and having a first disk stiffness. The disk drive
further includes a second disk disposed about the spindle motor hub and
having a second disk stiffness different than the first disk stiffness.
According to another aspect of the present invention, the second disk has
a second disk thickness different than a first disk thickness. According
to another aspect of the present invention, the second disk is formed of a
second material having a second material stiffness different than a first
material stiffness.
