Memory & Storage

Memory & Storage

1. Types of memory

   • Register
     • Small pieces of super fast memory, which stores things like addresses. These are volatile, meaning it does not save the data that it holds once the power in the computer is turned off. Registers are the quickest type of memory, and have the smallest capacity.
   • Cache
     • A quicker route than buses that allows frequently used data to be transmitted more efficiently. Cache is volatile and can vary in different sizes and levels.
   • ROM
     • Random Access Memory is the main type of memory used. Programs and data are loaded from the hard disk/solid state storage to RAM for processing. RAM’s capacity is measured in gigabytes. It is volatile and quicker to access than ROM but data travels slower than cache and registers.
   • RAM
     • Read Only Memory is the only type of primary memory that is non-volatile. This storage is significant, as it stores the first instructions to execute when the power is turned on.

2. Central Processing Unit

   • The CPU's purpose is to fetch and execute instructions
   • Components
     • Cache
       • Fast access memory for frequently used instructions and data.
     • Registers
       • Small fast memory used to help fetch and execute instructions.
     • Arithmetic logic unit
       • Performs calculations
     • Logic unit
       • Decodes instructions and sends signals to control how data moves around the CPU.
   • Factors affecting the CPU
     • Number of cores
     • Clock speed
     • Cache speed