Hard disk controller having multiple, distributed processors. A novel approach is presented by which a separate and dedicated processor is provisioned to service each of a plurality of control loops within a hard disk drive (HDD) controller. For example, a first processor is implemented to service a servo control loop, a second processor is implemented to service channel interfacing, and a third processor is implemented to service host interfacing. In some embodiments, the channel and host interfacing are performed using protocol processors implemented within each of a disk manager module and a host manager module, respectively.