STORAGE

STORAGE

1. OPTICAL STORAGE

   • a laser light creates marks in a pattern on the disk
   • a laser light detects where the marks are and translates this into a readable format
   • lasers read and write data using light
   • ADVANTAGES AND DISADVANTAGES
     • ADVANTAGES
       • media is very portable, especially when compared to a hard disk
       • it is inexpensive when only a small amount of data needs to be stored e.g. less than 10GB
       • it is immune to magnetic fields, unlike magnetic data can be damaged
     • DISADVANTAGES
       • the media is not as robust as magnetic or solid state alternatives . Disks can easily be scratched or broken
       • it is slower to write to than other types of media. it is also slower to access data from , compared to a magnetic or solid state hard disk
       • although it is inexpensive for storing small amounts of data the cost would be prohibitive for storing terabytes of data

2. SOLID STATE STORAGE

   • this is made of microchips (switches)
   • the state of the switches determine if a 1, or 0 is stored
   • data is recorded onto solid memory chips without any moving parts
   • ADVANTAGES AND DISADVANTAGES
     • ADVANTAGES
       • it is faster to access data from compared to a magnetic hard disk
       • it is robust. there are no moving parts unlike a magnetic hard disk so it is less likely to be damaged
       • it is very portable compared to other storage technologies
     • DISADVANTAGES
       • SSD are expensive compared to an equivalent magnetic hard drive
       • solid state storage has a limited number of erase/write cycles

3. MAGNETIC STORAGE

   • head moves across the medium and changes how magnetised that part of the medium is
   • Example: one level of magnetism will be at 1, a second will be at 0
   • mechanical parts move over the disks surface to read and write data magnetically
   • ADVANTAGES AND DISADVANTAGES
     • ADVANTAGES
       • huge storage capacity - measured in terabytes (TB)
       • cheapest out of the three storage technologies in terms of storage per gigabyte
       • data can be stored for a long period of time
     • DISADVANTAGES
       • magnetic fields can corrupt/damage the stored data
       • hard disks have mechanical moving parts. These can be damaged or wear out over time
       • it is slower to access data from than media using flash technology e.g solid state disk
       • not as portable as other storage technology - it is physically - if is integrated into a computer