What Is a CPU? What Does It Do in Your Computer?

The CPU or Central Processing Unit is a small square chip located on the computer’s motherboard. It is made by inserting millions of transistors into a single chip. Because they perform the most essential functions of your computer, people that are looking to buy or build a computer research a great deal about them. In this article, I will discuss in detail how they work and affect your computer.

Why Is the CPU Important?

The CPU is called both the heart and the brain of a computer. They play a critical role in processing and computing all data in your PC. When you go to perform an action on your computer, it is broken down into a set of mathematical functions. This can be as simple as moving your mouse across the screen or turning your PC on. The CPU then processes all these inputs to give you the desired result. The performance of your computer greatly depends on the CPU and how well it communicates with the other parts.

Brief CPU History

William Shockley, John Bardeen, and Walter Brattain invented the transistor in 1947. The discovery was such an important milestone that they were jointly awarded the Noble Prize. A semiconductor device that conducts electric signals, transistors are basically the building block of a CPU. The first transistors were about hand size. This discovery changed CPU manufacturing as transistors enabled the storage of larger data on smaller devices.

Another ground-breaking invention in the history of CPUs was the first integrated circuit built by Robert Noyce and Jack Kilby.

The integrated circuit is an electronic circuit integrated into a semiconductor material, generally silicon. The integrated circuit was an important invention because it led to the production of microchips. These tiny chips contain billions of transistors, storing large amounts of information and powerfully executing massive mathematical operations. The introduction of this technology amplified the computing power we now know today.

CPUs used to take up a significant amount of space. With the continued progression of this technology, we are now able to make them much smaller. We are able to make CPUs into a tiny chip called a microprocessor. They can be incredibly small, measuring up to only 45 nanometers. They are continuing to get smaller in size, but they are also increasing in power and efficiency.

Ryzen CPU on motherboard

CPU Processor Types

Advanced Micro Devices (AMD) and Intel are the two major companies producing microprocessors. Ryzen chips are AMD’s latest generation of processors. On Intel’s side, Atom, Pentium, and Celeron are the basics, while i-core and xenon are the newest performance-driven processors.

So What Does the CPU Actually Do?

All information fed into the computer is translated into binary code- a code with sequences of 0 and 1. The CPU receives this information and transfers it to the Arithmetic Logic Unit. The ALU does all the logical and mathematical operations and sends the data to the CPU. Then the CPU moves the response to the respective output device.

The CPU processes information in three steps called the instruction cycle or the Fetch-Decode-Execute cycle.

Intel CPU installed on motherboard

Step 1 – Fetch

The CPU fetches the instruction from the program counter and copies it to the Memory data register. From here, the CPU copies the information to the instruction register for instruction decoding. Meantime, the PC gets ready to fetch the next instruction.

Step 2 – Decode

The control unit deciphers the code and determines what instruction to perform. 

Step 3 – Execute

The control unit sends the decoded information to the relevant part of the CPU. If the instruction involves arithmetic or logic, the data goes to the ALU, and instruction is executed.

How Does It Affect Your PC?

The CPU is one of the most critical components of the computer. It is the CPU that coordinates the different parts and components, allowing you to run applications and execute tasks. To enable faster operation of functions, microprocessors today have multiple cores in a single computer.

AMD processor installed on motherboard

Multi-Core Processors

Multi-core processors contain several cores on a single chip where each core can perform tasks. For example, if you have opened two or more apps, each core will handle a different app. Thus, your data is processed faster, and you can multitask more efficiently.

Microprocessors vary significantly depending on the number of cores in the processor.

Single-core CPU is the oldest type. It executes only one command at a time. Hence it is much slower. Feeding single-core CPUs with multiple operations will drastically reduce its speed and performance.

Dual-core consists of two strong cores. It is like a computer with two brains, acting as one. Dual-core CPUs provide a better multitasking experience than single ones.

Quad-core processors function much better and efficiently as they have four cores. Here the workload is divided between the cores enabling faster operation of apps and effective multitasking. Quad-core is popular with budget gamers and workplace individuals.

CPUs with a higher core count include hexa-core with six cores, octa-core with eight cores, and deca-core with ten cores. Generally, a higher number of cores will enable better performance and speed. Heavy gamers benefit from the higher core counts, but they are generally more expensive. Hexa core with six cores is usually considered an affordable option for gamers.

When multitasking, multiple cores will enable you to process the information with greater ease. They consume less energy and don’t overheat as easily.

transistors on motherboard

CPU Clock Speeds

Another aspect that influences the performance of your computer is the clock speed of your processor. To put it simply, it is a single electronic pulse of a CPU. Clock speed is measured in hertz. 1 MHz equals one million cycles per second, and 1GHz is equal to 1 billion seconds per second. For example, a CPU with 3.6 GHz can execute 3.6 billion cycles per second.

However, unlike core numbers, higher clock speed is not always equal to higher performance. This is because different CPU brands handle instructions differently. Some CPUs can complete multiple instructions in one clock cycle, while others can take multiple clock cycles to execute a single instruction. Hence newer designs of CPU with lower clock speed can outperform older ones with higher clock speed.

Thermal Power Design

CPUs consume power in Watts. A processor with higher power consumption or thermal power design will also generate more heat. Hence, for optimal functioning of your computer, you must also consider thermal power design. 

Final Words

CPUs have developed a lot over the years, with new improvements constantly coming out. This may lead many people to question what they actually do. CPUs are the heart and brain of your computer. They control and coordinate all of the functions your PC conducts in a fraction of a second. Without the introduction of CPUs, who knows what computers would look like today.