Since the obvious objective in using a hard disk is to transfer data to the hard drive and onto the disks, or off the disks and out of the drive, the rate of data transfer is of paramount importance. Traditionally, real transfer rate metrics have been very underrated and given almost no attention compared to positioning specifications like seek time . The only transfer specification that is really commonly mentioned is the speed of the interface, which is actually the least important indicator of overall disk performance. Before we look at transfer specifications, we need to have a short word about terminology.
Data transfer occurs in two main steps.
For a write, the process is reversed. They are usually not the same, and in some cases can differ by an order of magnitude. Internal transfer rates are further broken down into the media transfer rate and the sustained transfer rate, and further complicating things is the fact that transfer rates are not constant over the surface of the drive. It sounds impossible to get a handle on, but it's not that bad once you place it all in the proper context and perspective, and that's exactly what we will do in this section. This page has been served 5192 times.