Abstract: An apparatus and method for a computer system having at least three disk drives in a storage array in which the rotational speed and angular position of the disk spindles are synchronized. At least two of these disks store data and at least one disk stores parity. All disks have corresponding tracks and sectors, however, the corresponding sectors of the parity disk are skewed in angular position so as to allow adequate time for the disk controller to read existing data from data disk sectors, calculate parity for new data to be written, and write the calculated parity to the corresponding sectors of the parity disk all during the same revolution of the disks.