HP Vectra VEi8 HP Vectra VEi7, VEi8 & VLi8, Technical Reference Manual (V - Page 23

Core Components and Technologies Mass-Storage Devices On top of improved timing margins, the protocol of Ultra-ATA also implements a significant feature new to ATA called Cyclical Redundancy Check (CRC) to provide data protection verification. CRC is calculated on a per-burst basis by both the host and the drive, and is stored in their respective CRC registers. At the termination of each burst, the host sends the contents of its CRC register to the drive, which compares it against its own register's contents. For even greater integrity, the protocol can be used at speeds slower than its maximum 33MB/s. In these cases, signal and data integrity will still surpass that of Fast ATA and earlier protocols at a given burst transfer rate. In fact, the slower the Ultra-ATA transfer speeds, the greater the integrity margins. To access HP's white paper on the Ultra ATA/33 protocol, refer to www.hp.com/desktop/library/wp.html. S.M.A.R.T. Technology S.M.A.R.T. or Self Monitoring Analysis and Reporting Technology allows the hard disk drive to report certain types of degradation or impending failure. This allows the operating system to take the necessary precautions and warn the user. The system is comprised of software that resides both on the disk drive and on the host computer. The disk drive software monitors the internal performance of the motors, media, heads, and electronics of the drive, while the host software monitors the overall reliability status of the drive. The reliability status is determined through the analysis of the drive's internal performance level and the comparison of internal performance levels to predetermined threshold limits. 23