Secondary Storage

• Slower (than primary storage) because it is not directly accessed by the CPU. • Typically larger in storage size (compared to primary memory). • Used for long-term storage of data and files because it is non-volatile. • Includes magnetic, optical and solid state storage.

Maximum amount of data that can be stored on the device

The strength of the device to last without breaking.

How easy it is to carry the device around.

How quickly data on the device can be read or edited.

The average price it costs to purchase a storage device.

The likelihood of the device continuing to perform well over time.

• A magnetic hard disk drive (HDD) is the most common form of secondary storage within desktop computers. • A read/write head moves nanometres above the disk platter and uses the magnetic field of the platter to read or edit data.

• Large capacity and cheaper cost per gigabyte than solid state. • Not durable and not very portable when powered on because moving it can damage the device. • Slow access speed but faster than optical storage.

• Optical storage uses a laser to project beams of light onto a spinning disc, allowing it to read data from a CD, DVD or Blu-Ray.

• Low capacity: 700 MB (CD), 4.7 GB (DVD), 25 GB (Blu-ray). • Not durable because discs are very fragile and can break or scratch easily. • Discs are thin and very portable. Also very cheap to buy in bulk. • Optical discs have the Slowest access speed.

• There are no moving parts in solid state storage. • SSDs (Solid State Drives) are replacing magnetic HDDs (Hard Disk Drives) in modern computers and video game consoles because they are generally quieter, faster and use less power.

• High capacity but more expensive cost per gigabyte than magnetic. • Usually durable but cheap USB sticks can snap or break. • The small size of USB sticks and memory cards mean they are very portable and can fit easily in a bag or pocket. • Solid State storage has the fastest ACCESS SPEED because they contain no moving parts.

• An obsolete type of magnetic storage is a floppy disk but these have been replaced by solid state devices such as USB sticks which are much faster and have a much higher capacity. • Another type of magnetic storage that is still used is magnetic tape. Magnetic tape has a high storage capacity but data has to be accessed in order (serial access) so it is generally only used by companies to back up or archive large amounts of data.

CD, DVD, Blu-Ray

• A USB flash drive (USB stick) is another type of solid state storage that is used to transport files easily because of its small size. • Memory cards, like the SD card in a digital camera or a Micro SD card in a smartphone, are another example of solid state storage.