1. An apparatus comprising a cache manager configured to force a retention of readback data in a cache memory after a transfer of said data to a host device, wherein at the time of said transfer the cache manager compares a time parameter to a time threshold and compares a locality parameter to a locality threshold, forces said retention of the readback data if both said thresholds are met, and releases the readback data from the cache memory if at least one of said thresholds is not met.