Common types of storage - solid state storage (flash storage)
Introduction
There are three main types of technology for storage. These are optical, magnetic and solid state technology.
Solid state devices (also known as flash storage)
Solid state devices include USB pen drives, SD cards, micro SD cards, newer types of hard drive, the SIM card that goes in your mobile phone and smart cards such as chip and pin credit and debit cards.
Solid state devices store data in binary patterns using billions of tiny low-voltage switches called transistors. If a switch is open, then this represents a binary one because the transistor keeps its charge - the charge is not able to drain away. If it is closed, this represents a binary zero because the charge has a path to escape.
Advantages and disadvantages of solid state devices
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- Solid state devices have no moving parts. That means they can't get worn out.
- They are not quite as easily damaged by bangs and knocks as optical and magnetic devices.
- Solid state devices need very little power to work. They can get all the power they need from the device that they are plugged into.
- Solid state devices are fast compared to magnetic and optical devices. One way to dramatically speed up a computer is to change the magnetic hard drive for a solid state one.
- They cannot hold as much data as some alternative storage devices such as hard drives.
- Solid state hard drives are more expensive that magnetic hard drives.