Central Processing Unit

A central processing unit (CPU), also known as a processor, is located on the motherboard. The CPU carries out the instructions of a computer program known as software by performing the basic arithmetical, logical, and input/output operations of the system. Its function is to execute programs machine language code and store it in main memory RAM in the computer, including performing calculations, and running programs. It does this by repeating the ‘fetch-and-execute’ cycle over and over, it repeatedly fetches a machine language instruction from RAM and then executes it. The CPU is often called the brains of the computer where most calculations take place. In terms of computing power, the CPU is the most important element of a computer system but works as part of a broader, more diverse ecosystem that includes RAM and other elements of the computer. Motherboards support specific types or ranges of CPUs, so check the motherboard manufacturer’s specifications before attempting to replace or upgrade a CPU in a computer. Most CPUs come with heatsinks and a fan that fits on top of the CPU to help dissipate heat, CPUs generate a lot of heat so water cooling a CPU is the best option for high-end gaming or graphics machines. 


The two normal components of a CPU are:​​

  • Control unit (CU), which extracts instructions from memory and decodes and executes them - calling on the ALU when required.

  • The arithmetic logic unit (ALU) performs arithmetic and logical operations.