The hard disk

The hard disk is designed for permanent storage used when working with computer information. Unlike RAM, whose contents are erased when you turn off your computer, the information recorded on the hard disk, when you turn off your computer is stored.

The hard disk is designed for permanent storage used when working with computer information

The hard disk has single axis - spindle, which has multiple magnetic plates made of metal or plastic. On both sides of the plate are covered with a thin layer of magnetic material. Magnetic hard disk plate mounted on the spindle and rotate on it as a single unit. The spindle is rotated by a special motor provides the desired rotational speed, for example 5400 rev/min., 7200 rev/min., 10000 rev/min.

Above each side of each magnetic disk is a private read/write head. All the heads are joined together and move together radially relative to the plates. This provides quick access to any plate.

Computer hard disk drive has a few parameters that indicate a significant effect on price levels and on the performance of the computer in general.

  1. The maximum amount of stored information. A modern hard drive may have a capacity from 20 up to several terabytes.
  2. The average access time. This is the time for which the hard drive moves its magnetic heads to the desired sector. The lower this figure - the better hard drive.
  3. The rate of exchange of the data interface. The higher the speed - the faster the hard drive will give the information in memory.
  4. Spindle speed. Has impact on data retrieval time, the hard disk and is generally 5400 rev/min., 7200 rev/min., 10000 rev/min.
  5. Type interface. The hard drive can be connected to your computer in different ways, ie it may have a different interface. To date, a proliferation of three types of interfaces: IDE, SATA, SCSI.
  6. Noise level is noise that produces hard disk mechanics by its work. It is indicated in decibels. Silent device drives are considered noise of about 26 dB or less. The noise is the the spindle rotation noise and positioning noise. To reduce the noise from the hard drives used the following methods: software, built into most modern drives; the use of sound-absorbing devices, fixing discs on rubber or silicone washer or a complete replacement of mounting a flexible suspension.
  7. Buffer called intermediate memory, designed to smooth out differences in the read/write speed and the transmission interface. In modern drives it usually ranges from 8 to 128 MB.
  8. Resistance to shock is resistant hard drive to sudden changes in pressure or impact, measured in terms of the permissible overload.