Hard disk

Hard Disk

Hard Disk is an storage device which conserve permanently the data and is not clean when the computer is turn off, is a device that store a large volume of information.

Hard Disk Components

Hard disk components A typical hard disk has two electric motors; a spindle motor that spins the disks and an actuator (motor) that positions the read/write head assembly across the spinning disks.

1. The platters are the actual disks inside the drive that store the magnetized data.
2. The magnetic layer on the platters has tiny domains of magnetization that are oriented to store information that is transferred through the read/write heads.
3. The spindle motor is built right into the spindle or mounted directly below it and spins the platters at a constant set rate ranging from 3,600 to 7,200 RPM. The motor is attached to a feedback loop to ensure that it spins at precisely the speed it is supposed to.
4. The read/write heads read and write data to the platters.

Types Of Hard Disk

• Hard disk drive: Hard disk drives have been the dominant type of storage since the early days of computers. A hard disk drive consists of a rigid disc made with non-magnetic material which is coated with a thin layer of magnetic material. Data is stored by magnetizing this thin film. The disk spins at high speed and a magnetic head mounted on a moving arm is used to read and write data. A typical hard disk drive operates at a speed of 7,200 rpm (rotations per minute), so you will often see this number as part of the technical specifications of a computer.

• Solid-state drives: (SDD) are a relatively new alternative to more traditional hard disk drives. Solid-state drives do not have moving parts, and data is stored electrically instead of magnetically. Most solid-state drives use flash memory, which is also used in memory cards for digital cameras and USB flash drives.