Computer Hardware CPU

Computer Hardware CPU

1. Central Processing Unit (CPU)

   • The Purpose of the CPU is to process data.
     • To carry out the Fetch Decode and Execute cycle. This is the cylce which processes everything that the computer wants to do
       • Fetch: In this step the CPU fetches data and instructions from main memory where it is then transfered to an internal memory area and waited to be decoded
         • Decode: CPU has to decode where it makes sense of the code and the instruction that it has just fetched.
           • Execute: Carry out the data/ Complete the process
   • Cache
     • Small amounts of memory close to the CPU which is used to temporarily hold instructions
     • The larger the cache size, the better the performance as it is able to store more data locally. However this can be very expensive
   • Cores
     • If a CPU contains multiple cores then it is able to carry out multiple tasks at once
     • CPUs can contain one or more processing units - each of these units are called cores.
   • What is clock speed?
     • Clock speed indicates how fast the CPU can run.
     • Clock Speed is measured in cycles per second.

2. Memory

   • ROM: Read only memory
     • This is normally used for storing the boot up system so you dont have to install it every time you start up your computer
     • ROM still stores the data even without power
   • RAM: Random access memory
     • Anything stored in the RAM is lost as soon as the computer loses power