Please note that the content of this book primarily consists of articles
available from Wikipedia or other free sources online. Spin-up refers to
the process of a traditional (non-solid state) hard disk drive
accelerating its platters from a stopped state to an operational speed.
The period of time taken by the drive to perform this process is
referred to as its spin-up time, the average of which is a S.M.A.R.T.
attribute. The required operational speed depends on the design of the
disk drive. Typical speeds of disks have been 2400, 3600, 4200, 5400,
7200, 10000 and 15000 revolutions per minute (RPM). Achieving such
speeds can require a significant portion of the available power budget
of a computer system, and so application of power to the disks must be
carefully controlled.
