What is a CPU: Functions, How it Works, and Types

what is a cpu functions how it works and types.

When looking for a new PC or laptop, the specifications for the type of CPU that we can find on the new device must be listed. But most people don't know that they are so important. When we decide to choose between AMD and Intel, dual or quad-core, it can be difficult to tell the difference and why it matters. Most people also still don't know What is a CPU?

What are CPUs?

The Core Processing Unit (CPU) is often referred to as the brain of the computer. While the CPU is only one of many processing units, this Hardware is one of the most important. Because it is part of the computer that performs calculations, actions, and executes programs.

The CPU takes instructional input from the computer's RAM, decodes and processes actions, before providing output. CPUs are in all kinds of devices from computers and laptops, to smartphones, tablets, and smart TVs. This small square chip is usually placed on the motherboard of the device and interacts with other hardware to operate our computer.

CPU Functions

Actually, the main function of the CPU is to process the instructions given to the computer. This is why the CPU is known as the “brain” of the PC. Every operation that is performed, such as when you type on the keyboard, open and close programs, and save files. It's all done by the CPU.

How CPU Works

There have actually been so many improvements over the years since CPUs first appeared. However, the basic function of the CPU remains the same which consists of three steps: Fetch, Decode, and Execute.

1. Fetch

As we would expect, fetch involves receiving instructions. Instructions are represented as a series of numbers and passed to the CPU from RAM. Each instruction is only one small part of any operation, so the CPU needs to know the next instruction to come. The address of the current instruction is held by the program counter (PC). The PC and instructions are then entered into the Instruction Register (IR). The length of the PC is then increased to reference the address of the next instruction.

2. Decode

After the instructions are fetched and stored in the IR, the CPU passes the instructions to a circuit called an instruction decoder. This is the part to convert the instruction into a signal that must be passed to another part of the CPU to execute.

3. Execute

In the final step, the instructions are sent to the relevant part of the CPU for completion. The result is usually written to the CPU register, where the result can be referenced by the next instruction. Think of it like a memory function on a calculator.

How Many Cores Are Needed

Early CPUs were created to have only one core. This means that the CPU is limited to only one task and this is one of the reasons why computers are often relatively slow and time-consuming. But after pushing single-core CPUs to their limits, manufacturers started looking for new ways to increase CPU performance. Finally, multi-core processors were created. Today, we may hear terms like dual, quad, or even octo-core.

A dual-core processor for example only has two separate CPUs on a single chip. By increasing the number of cores, the CPU is able to handle multiple processes simultaneously. This has the effect of increasing performance and reducing processing time. Dual-core soon gave way to quad-core processors with four CPUs, and even octo-core or eight-core processors.

Understanding Specifications

Having knowledge of CPU operation along with different brands and core numbers helps a lot. However, there are plenty of options out there even with the same high-level specs. There are several other specifications that can help us decide when we want to buy a CPU.

1. Mobile vs Desktop

We know that a computer is a large static electronic device powered by a constant supply of electricity. But with the invention of the smartphone, we realize that we basically carry our computers with us wherever we go. The mobile processor is optimized for efficiency and power consumption so the device battery lasts as long as possible.

Many Manufacturers take the initial naming of mobile processors the same as desktops. Although this is a different product. The mobile processor prefix has “U” for ultra-low power, “HQ” for high-performance graphics, and “HK” for high-performance graphics with overclockability. The desktop prefix includes “K” for overclockability, and “T” for optimized power.

2. 32 or 64-bit

A processor does not receive a constant stream of data. Instead of receiving data in small chunks known as “words.” The processor is limited by the number of bits in a word. When 32-bit processors were first designed, it seemed like the word size was huge. Moore's Law persisted, and suddenly computers could handle more than 4GB of RAM, and that led to the creation of new 64-bit processors.

3. Thermal Power Design

Thermal Power Design is a measure of the maximum power in Watts that the CPU will consume. Although the lower power consumption is definitely good for the electricity bill and it causes less heat.

4. CPU Socket Type

To make a fully functional computer, the CPU must be attached to other components via the motherboard. When choosing a CPU, we need to make sure that the CPU and motherboard socket types match.

5. L2 / L3 Cache

The L2 and L3 caches are fast onboard memory for the CPU to use during processing. The more we have it, the faster the CPU performance.

6. Frequency

Frequency refers to the operating speed of the processor. Before multi-core processors, frequency was the most important performance metric between different CPUs. Despite the addition of features, it is still an important specification to consider. For example, it is possible for a very fast dual-core CPU to outperform a slower quad-core CPU.

Brain Operation

The CPU is actually the brain of the computer. This hardware performs all the tasks we normally associate with computing. Most of the other components of the computer are actually there to support the operation of the CPU. Improvements made in processor technology including hyper-threading and multiple cores played an important role in the Technical Revolution.


So What is a CPU? The central processing unit (CPU) is the unit that does most of the processing inside the computer. To control instructions and data flow to and from other parts of the computer, the CPU relies heavily on the chipset, which is a group of microchips located on the motherboard.

Hopefully, this article about What is a CPU: Functions, How it Works, and Types, gives you a little insight. Also, read an article about What Is a Data Center And Why Is It Important? that you may need to know. Thank you.

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