Main Memory/CPU

Main Memory/CPU

1. RAM

   • RAM stores information for a period of time while the computer is running.
   • RAM is a type of volatile memory that means when the PC is turned off all the info gets wiped off it.

2. ROM

   • ROM stands for Read only memory. ROM only lets the computer read the data but not write it.
   • ROM is used when the computer starts up as it caries out a list of set instructions that have to be followed

3. Cache

   • Stores data and speeds up the processor. It is based in the CPU it retrieves data from the RAM

4. Volatile memory

   • Memory that is on the computer while running but is deleted once the PC is turned off

5. Non - Volatile

   • Memory that is kept when the computer is turned and not deleted.
   • An example of Non Volatile is a hard drive

6. Virtual Memory

   • Virtual memory is stored in secondary storage
   • It's used when the RAM is full, it's much slower because it's much bigger that the RAM. To not use Virtual memory you could buy more RAM or close some applications down

7. CPU

   • Clock Speed
     • The number of independent processors in the CPU which run the fetch decode execute cycle simultaneously. Cores The number of fetch decode execute cycles a CPU can perform per second. This is measured in hertz (Hz).
   • Cores
     • The number of independent processors in the CPU which run the fetch decode execute cycle simultaneously.
   • Hertz
     • The SI unit of frequency, equal to one cycle per second.
   • Fetch, Decode and Execute
     • Fetch, decode and execute cycle is when information is wanted by the CPU, it is the decoded into an image ready to display it on the scree