Magnetic Storage

• Magnetic storage


  The most common type is the Hard Disk Drive (HDD)
• Storing a bit

  1. The value of each bit of data (0 or 1) is represented as a positively or negatively charged magnetic particle

  2. These particles are part of a magnetic disk called the platter
• Accessing data

  1. Data could be stored anywhere on the disk, and so to read/write data we first need to find the location on the disk

  2. A magnetic read/write head is used to access the data while the platter spins
• HDD


  • Has moving parts
  • Generally reliable, but any device with moving parts will be subject to wear-and-tear
  • Can be damaged by shocks, not robust
• Magnetic media

  • Low cost per unit capacity
  • Low speed due to high number of moving parts
  • Reliable and tends to last for a long time
  • Not robust, tends to break on impact or during vibrations
  • Can store a large quantity of data in a compact way
• Magnetic storage devices

  • Hard Disk Drives (HDDs)
  • Magnetic tape
  • Hybrid drives
• HDDs


  • Often used as the main form of secondary storage in a computer system
  • Hold the operating system, applications, and user data
• Magnetic tape


  • Used to be popular for distributing content such as audio, video, and software
  • Nowadays, only used for some video cameras and making backups
• Hybrid drives


  Combination of magnetic and solid state storage, offering the benefits of both systems