Power management is a set of protocols used to allow PCs to reduce the amount of power
that they consume, especially when they lie idle. Hard disk drives are always spinning
during operation, and the spindle motor is what is using the bulk of the power consumed by
the drive as a whole. Therefore, many power management schemes include a mechanism by
which the hard disk's spindle motor can be "spun down" after a certain amount of
inactivity, and then can be "spun up" (reactivated) when the system needs them
again.
There is some controversy surrounding this feature. First, there is some debate as to
whether or not dramatically increasing the number of times the drive spins up and down
(which power management does) is detrimental to the drive or could cause it to fail
prematurely. Second, there is some skepticism about how much energy is really saved, given
that the hard disk doesn't use that much power under normal operation to begin with. Certainly for laptop users power management is an important feature;
all laptop hard disks support power management via BIOS settings and/or operating system
controls.
Next: Hard Disk
Connectors and Jumpers
