Computer disc accesses necessitate the mechanical movement of a read/write head over a sequence of storage locations. The pattern of such random movement has a significant bearing on access times and its estimation is of primary importance to the meaningful prediction of performance. The procedure presented, which is based on a random walk description, allows such estimates to be derived quickly, incorporating any prior knowledge and partial information on data characteristics. Although only an approximation, it is able to produce good agreement with published measurements.

You do not currently have access to this article.