The frequency with which data is accessed within the system may be periodically monitored and a corresponding access frequency quantifier assigned to the data is updated accordingly. The data access frequency quantifier may be associated with a storage device zone speed quality rating. The association between data access frequency quantifiers and the storage device zone speed quality ratings may be made in a hierarchical association such that quantifiable differentials may be ascertained between a particular access frequency quantifier and a storage device zone speed quality rating. In this manner, when no storage zone having a speed quality rating that is associated with data having a particular access frequency quantifier is available for storage of the data, a storage zone having a speed quality rating more proximate the speed quality rating associated with the access frequency quantifier may be identified for migration.