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Unformatted text preview: e rigid construction of hard disks also allows them to spin at much greater speeds
than floppy disks, resulting in faster data access. Floppy disks tend to bend at higher
speeds due to their flexible construction. For example, a floppy disk normally spins at
360 rpm, whereas hard disks spin at 3600 rpm, 5400 rpm, or even 7200 rpm.
In most hard disk drives, the disk(s) keep spinning continuously. In contrast, the
diskette of a floppy disk drive is set in motion only when a command is issued to read
from or write to the disk. This also contributes to faster data access for hard disks as
compared to floppy disks.
Advantages and Limitations of Magnetic Disks
As a secondary storage device, magnetic disks have the following advantages:
Unlike magnetic tapes, which support sequential access of data, magnetic disks
support direct access of data. Hence they are more suitable for a wider range of
2. Due to its random access property, magnetic disks are often used simultaneously by
multiple users as a shared device. For example, Winchester disks and disk packs are often used as on-line secondary storage devices, in which case they store data of multiple
users of the computer system. A tape is not suitable for such type of usage due to its
Magnetic disks are suitable for both on-line storage of date. For example,
Winchester disks and disk packs are often used as on-line secondary storage devices,
whereas floppy disks and zip disks are used as off-line secondary storage devices. In fact,
the high-capacity Winchester disks have made it possible for today's most personal
computer users to enjoy the convenience of having all data and software readily
accessible at all times.
4. Except for the fixed type Winchester disks, the storage capacity of other magnetic
disks is virtually unlimited because as many disks are required can be used for storing
very large data sets.
5. Due to their low cost and high data recording densities, the cost per bit of storage is
low for magnetic disks. An additional cost benefit is that magnetic disks can be erased
and reused many times.
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- Spring '14