A storage disk for a hard disk drive includes a homogeneously-formed body
region, a first side region and a second side region. The body region
includes a first body side and a second body side opposite the first body
side. The first side region is secured to the first body side and the
second side region is secured to the second body side. In one embodiment,
the first side region is adapted to store data and the second side region
is not adapted to store data. The first side region includes a plurality
of layers formed from different materials relative to one another. The
first side region has a first density that is different than a second
density of the second side region. In one embodiment, the first side
region has a mass that is different than a mass of the second side
region. In an alternative embodiment, the first side region has a
thickness that is different than a thickness of the second side region.