Storage devices Flashcards
What is a (magnetic) hard disk and how does it store data?
A magnetic hard disk stores data on a series of metal plates. To read or write data a moving arm finds the location on the disk and either magnetises, demagnetises or reads the magnetic state of the area.
What are the disadvantages of magnetic hard disks?
The disk has moving parts so can easily be damaged if dropped or shaken so cannot be used to transport data easily. The also have longer access times than other forms of secondary storage.
What are the advantages of magnetic hard disks?
The technology used has been around for longer than other storage types so can be found at cheaper prices. Because of this hard disks often are built to store large quantities of data i.e. 1TB
What is a solid state drive (SSD) and how does it store data?
A solid state drive uses series of transistors to store an electrical current in a non-volatile format. The data is overwritten by using a surge of current to rewrite the memory hence their other name - flash drives,
What are some of the disadvantages of SSDs?
SSDs are more expensive to produce due to their complex structure making them far more expensive than hard disks. This means the’re also built to store less data; commonly around 200GB.
What are some of the advantages of SSDs?
SSDs have extremely quick access times as they store data as an electrical current so feature no moving parts. This also makes them less fragile so can be used as a portable data storage i.e. memory sticks.
What is an optical drive and how does it store data?
An optical drive or disk drive uses lasers to scan the surface of a metal disk or CD. The lasers can also rewrite the data by changing the surface dependant on the disk and drive.
What are some of the disadvantages of an optical drive?
Optical drives take a period of time to begin spinning the disk during which memory cannot be read. They also have slow access times. The disks used to store data also often can store very little data on them.
What are some of the advantages of optical drives?
Optical drives are a part of most computer systems so disks can be distributed by retailers for private use by anyone. The disks are also cheap to manufacture as blank ones can cost as little as 2-4p each.
