A hard disc drive includes a base having a moving region in which an air
damping ramp adjacent to a recording surface of a disc, a slider, and a
driving unit which holds the slider, move. A bottom of the moving region
is lower than the air damping ramp, and has a channel that is recessed at
the bottom of the moving region and extends along a moving path of the
slider. Thus, the hard drive reduces a vortex that forms around a head
gimbal assembly (HGA) due to an application of insufficient preload onto
HGA or a defective HGA. Accordingly, vibration of the HGA due to the
vortex decreases, thus rendering a position error signal (PES) more
accurate and reliable.