It has been discovered that system operational characteristics (e.g., power level, clock frequency, processor utilization, operating system time slice utilization, size and age of queued jobs) may be used to predict storage access requirements for the system. By predicting the storage access requirements of a system, a storage subsystem may be advantageously controlled to anticipate storage accesses. A storage device or array of such devices can be configured to operate, for example, at selected speeds no greater than that required to process the predicted storage access requirements. The storage access prediction may be based, for example, on the frequency and voltage at which a processor is running or based on other system performance indicators such as job backlog and age and size thereof. Various controllable characteristics such as the speed of a hard drive's storage media, the current applied to a read/write head, etc., can be increased or decreased continuously or to discrete values in response to moving average indicators which provide advance warning of potential processing, and therefore potential storage access, swings.