Computer Systems

Lisa She- Yin

Central Processing Unit (CPU)

Computer systems have a Central Processing Unit, also known as CPU, at their core. This performs all the calculations, operations and tasks that need to be done while someone uses the computer. The speed of the CPU is normally measured in Gigahertz (GHz). Companies that make CPUs include Intel and AMD. In general, the higher the speed, the faster the computer system will run.

Random Access Memory (RAM)

Another measure that affects the computer performance is the amount of RAM (Random Access Memory). This stores data that is currently in use- the more memory you have the more data and programs you can have open at any time. A modern desktop PC will probably have about 1-8 Gigabytes of RAM. Memory that loses its data when the power is removed is known as volatile memory.

Hard Disk Drive (HDD)

For permanent storage of data, most computers still have a hard disk drive or HDD. These work by magnetically storing binary code onto a metal disc. A modern computer will probably have a hard disc drive that can store between 500 Megabytes to 1 Terabyte of data. There are 1024 Gigabytes in 1 Terabyte.