Abstract: A method of operating a disk drive having a cache provides for adapting the amount of prefetch. The drive also has an intelligent interface for communicating with a host, and a magnetic disk. The cache is divisible into a number of segments, and employs a cache control structure including a cache array with a cache array entry. When the drive receives a first command, the method provides a step of performing a scan of the cache to assign the first command to a segment. The method further includes the step of maintaining the cache array with a cache array entry for each one of the number of segments, where each cache array entry classifies a segment by a cache access type, wherein the cache access type is selected from a plurality of access types including sequential and random. The method further includes the step of determining a limit on the amount of prefetch based on the cache access type for the first command and a cache environment variable. The limit may be a minimum prefetch or a maximum prefetch.