11.3 Access Speed

The rotation speed of the magnetic disk is constant, approximately 25.2 ms per rotation, regardless of which zone the head is located in. Therefore, approximately 12.6 ms is needed to transfer 1 block. As was mentioned previously, block size varies with location. Consequently, the closer to the periphery the data are located, the slower the per-byte transfer rate. The following gives the typical transfer rate for each zone.