METHOD FOR SETTING DATA CARRIER SPEED IN A DATA CARRIER DRIVE APPARATUS

摘要

A method is described for setting a disc speed in a disc drive apparatus (3)which is in data transfer communication (7) with a host system (2), wherein data transfer between carrier and drive apparatus takes place with a carrier/drive transfer rate (DDTR) and wherein data transfer between drive apparatus and host system takes place with a drive/host transfer rate (DHTR). A target speed different from the current speed is calculated; the expected carrier/drive transfer rate (DDTRex) at the target speed is calculated; and the drive/host transfer rate (DHTR) is compared to the expected carrier/drive transfer rate (DDTRex). The current speed is maintained if said comparison between drive/host transfer rate (DHTR) and expected carrier/drive transfer rate (DDTRex) indicates that a next speed change from the said target speed back to the current speed is to be expected if the speed would be changed to the said target speed.