What is a CPU
When looking a new PC or Laptop, the specifications will mention the CPU. When choosing between AMD and Intel, dual or quad-core, and i3 vs. i7 or i5 vs. i9, it can be hard to tell what the difference is and why it matters. Knowing which is best for you can be difficult. What most people look at when choosing a computer is the CPU, but what exactly is the CPU's function? This article will attempt to answer that.
The Central Processing Unit, or CPU, is often referred to as the brains of the computer. While the CPU only makes up one of many processing units, it is one of the most important. It is the part of a computer that performs calculations, actions, and runs programs. The CPU takes instructional inputs from the computer’s RAM, decodes and processes the action, before delivering an output. CPUs are in all sorts of devices ranging from computers and laptops, to smartphones, tablets, and smart TVs. The small chip is placed on the device's motherboard and interacts with the other hardware to operate your computer. The basic function of the CPU has remained the same consisting of three steps; fetch, decode, and execute, despite having been improved over the years since the first CPUs.
Fetching involves receiving an instruction. The instruction is represented as a series of numbers and is passed to the CPU from the RAM. Each instruction is only one small part of any operation, so the CPU needs to know which instruction comes next. The current instruction address is held by a program counter or PC. The PC and instructions are then placed into an Instruction Register, or IR. The PC length is then increased to reference the next instruction's address. Once an instruction is fetched and stored in the IR, the CPU passes the instruction to a circuit called the instruction decoder. This converts the instruction into signals to be passed through to other parts of the CPU for action. In the final step, the decoded instructions are sent to the relevant parts of the CPU to be completed. The results are usually written to a CPU register, where they can be referenced by later instructions. Think of it like the memory function on your calculator.
The CPU is the brain of the computer. It performs all the tasks that we would typically associate with computing. Most of the other computer components are really there to support the operation of the CPU. The improvements made in processor technology including hyper-threading and multiple cores played a key part in the Technical Revolution.