Western Digital Blue WD20SPZX Technical Reference Manual page 14

increased shock robustness and enhanced reliability while reducing power
consumption and acoustics.
Staggered Spin-Up: Native SATA feature that allows the system to control

whether the drive will spin up immediately or wait until the interface is fully ready.
CacheFlow™: WD's unique, multi-generation caching algorithm evaluates the

way data is read from and written to the drive and adapts "on-the-fly" to the
optimum read and write caching methods. CacheFlow minimizes disk seek
operations and overheads due to rotational latency. CacheFlow supports
sequential and random write cache. With write cache and other CacheFlow
features, the user can cache both read and write data. The cache can hold
multiple writes and collectively write them to the hard drive.
48-bit Logical Block Addressing (LBA): WD SATA drives support both 48-bit and

28-bit LBA and CHS-based addressing. LBA is included in advanced BIOS and
operating system device drivers and ensures high capacity disk integration.
Power Management: WD SATA drives support the ATA and Serial ATA power

management command set, allowing the host to reduce the power consumption
of the drive by issuing a variety of power management commands.
Automatic Defect Retirement: If the WD SATA drive detects a defective sector

while reading, writing, or performing offline data collection, it automatically
relocates the sector without end-user intervention.
Self-Monitoring, Analysis, and Reporting Technology (S.M.A.R.T.): S.M.A.R.T.

enables a drive's internal status to be monitored through diagnostic commands at
the host level and during offline activities. S.M.A.R.T. devices employ data analysis
algorithms that are used to predict the likelihood of some near-term degradation
or fault conditions. When used with a S.M.A.R.T. application, the drive can alert
the host system of a negative reliability status condition. The host system can
then warn the user of the impending risk of data loss and recommend an
appropriate action.
ATA Security: WD SATA drives support the ATA Security Mode Feature set. The

ATA Security Mode feature set allows the user to create a device lock password
that prevents unauthorized hard disk access even if the drive is removed from the
host computer. The correct password must be supplied to the hard drive in order
to access user data. Both the User and Master Password features are supported,
along with the High and Maximum security modes. The Master Password Revision
code is also supported.
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Description and Features
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