Computer Science Secondary Storage

Secondary Storage is necessary because

It stores data for long periods of time/It is robust and reliable/It is much cheaper per MB than main memory/It has more capacity /It is portable

Solid-State Storage Devices

have no moving parts. They store data inside electronic circuits, which can be set to store a 1 or 0. These devices are typically much smaller than magnetic devices. They can have a large capacity, but are more expensive./ This type is also called flash memory.

Optical Storage

is most commonly used to distribute media and software — movies and video games for example. /This type uses lasers to read and write data on a reflective surface. /These devices are typically small in capacity, but very cheap to produce.

Magnetic Storage

is the oldest form of storage, and has been in use since the 1920s (before computers were available). /Data is stored in series as polarized dots. The polarity (positive or negative) of the dot determines whether it stores a 1 or 0. These devices come in very large capacities and are generally inexpensive.

Solid-State Storage Advantages

Fast: With read speeds up to 550MB per second/ Lightweight: Typically much smaller than hard drives/Durable: They do not suffer mechanical faults /Low power consumption/Silent when in use

Solid-State Storage Disadvantages

Expensive cost per MB/Typically a lower capacity than hard drives/ Can be unreliable