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What is a Processor?

James Gallagher - January 04, 2021

What is a Processor?

A processor, or CPU, is a circuit board inside a computer that executes instructions on behalf of programs. Modern computer processors can process millions of instructions in a second. Processors are considered the main chip on a computer.

It’s hard to evaluate a new piece of technology without considering its processor. The trouble is that it’s difficult to decode what a processor does, even if you are a techie.

Processors are the brains behind a computer. They control the logic that performs calculations and run programs on your computer.

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In this guide, we’re going to talk about what processors are and what components make up a modern-day processor.

What is a Processor?

A processor is a piece of hardware that interprets the instructions that drive a computer. Processors are the brains of a computer with good reason. Without a processor, computers could not run programs.

Processors are also called Central Processing Units (CPUs). Technically, there is more than one processor in a computer, such as a Graphics Processing Unit (GPU). But, the CPU is arguably the most important one.

Processing units take instructions from a computer’s Random Access Memory (RAM). The CPU decodes and processes an action when an instruction is received. Then, the CPU delivers an output.

Intel and AMD are the most well-known businesses in the CPU industry for desktops, laptops, and server computers. Intel Core and AMD Ryzen are some of the most popular desktop processors. Apple, Nvidia, and Qualcomm are all mobile device CPUs.

Where is the Cental Processing Unit Located?

Processors are located on the motherboard of a computer. They attach to what a CPU socket, or a CPU slot. There is a lever next to a CPU which is used to ensure that it remains attached to the motherboard.

Parts of a Computer Processor

There are four components to a computer processor: the ALU, FPU, registers, and cache memory.

The Arithmetic Logic Unit (ALU) carries out all the arithmetic and logic operations. It operates with integer numbers, which are whole numbers. The Floating Point Unit (FPU), manipulates floating-point numbers, which are numbers that include a decimal.

Then there’s the register. The register holds instructions received from other parts of a computer. It tells the ALU what processes to carry out and stores the results of those operations.

Processors include L1 and L2 memory. This cache of memory allows the processor to store data locally, without having to retrieve it from the RAM. The inclusion of this component helps make a CPU quicker and more efficient.

How Does a CPU Work?

CPUs may come with more bells-and-whistles than ever before. At their core, they use the same set of processes. These processes are called the fetch-execute cycle. This cycle has three steps: fetch; decode; and execute.

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The first step in the fetch-execute cycle is fetching. It involves receiving – or “fetching” – an instruction. This instruction is sent from the RAM to the CPU.


The CPU processes an instruction using its decoder when it is sent from the instruction register. The CPU turns the instruction into a series of signals that can be interpreted by other parts of the CPU.


At the end of this process, the computer executes the decoded instructions. Instructions are sent to other parts of a processor to be executed. The CPU register saves intructions after execution. This helps improve the speed of a processor because it can remember some instructions it has processed.

CPU Specifications: A Quick Rundown

While CPUs all do the same thing – process instructions – the specifications for a CPU vary depending on its use case. Let’s discuss a few of the top specifications you should know about.

32 and 64-bit Processors

There are two main types of processors: 32 bit and 64 bit. These numbers refer to how many bits can be sent at the same time between different parts of the CPU.

32-bit processors became well-known for their power. More recently, computers have been able to process up to 64 bits. The higher the bit count, the faster the processor.

Clock Speed

Clock speed refers to how many instructions a CPU can process per second. Gigahertz (GHz) is the main unit of measurement for tracking clock speed. You’ll see gigahertz numbers a lot on processor specifications. The greater the clock speed, the faster a CPU will run.

Most of the time, it’s necessary to compare clock speed when you are evaluating CPUs from the same generation. This is because while clock speed is an influencing factor in the speed of a processor, there are other components that matter equally.

L2/L3 Cache

A CPU stores commonly used data in L2 and L3 memory. Instead of having to call on the RAM every time the CPU needs to process an instruction, the CPU can store some commonly-used instructions.

An L2 or L3 cache is quicker than RAM because it is part of the processor. The more cache you have, the faster your CPU.

How do Processor Cores Work?

In the old days of computing, a computer processor would have a single core. This means that it could perform one set of instructions at any given time. Hardware engineers have pushed this limit and today multi-core processors have become a standard. Multi-core processors have multiple cores. They can execute different instructions at the same time.

Most computers today have between two and four cores. You’ll hear these setups referred to as “dual” and “quad” core, respectively. Some processors have up to 12 cores, depending on their purpose. The more cores a CPU has, the more instructions the processor can interpret.

Processors with multiple cores are simply two or more CPUs on a single chip. A quad core processor is four CPUs, all on the same chip. A link exists between each core so they can work together.

i7 Processors and i9 Processors

Both i7 processors and i9 processors are commonplace on the modern computing market. You’ll find these terms used to describe the processors that laptops and desktops use.

i7 is a line of Intel CPUs. i7 processors have either four or six cores and frequencies between 2.6 and 3.7 gigahertz.

They have large amounts of cache memory which means they can store more instructions locally. Designers, gamers, and programmers often use this processor on account of its power.

i9 processors are a step above i7 processors. These processors are most common in desktops although some laptops do have i9 processors. This processor can be overclocked to up to 4.5 gigahertz. They are the top model on the market.

For most users, an i7 processor is more than enough. In fact, previous generations like the i5 is enough for a lot of people. If you are a gamer or someone else who needs a lot of computing power, you may want to splurge for an i9 processor.

Wrapping Up

CPUs are an essential part of a computer. It is responsible for processing the data that allows you to run programs on your computer. In recent years, there have been vast improvements made to CPUs.

The introduction of multi-core processors, as well as new innovations such as hyper-threading, allow our computers to operate faster and more efficiently. Now you’re ready to start talking about CPUs like a computing expert!

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James Gallagher

About the author: James Gallagher is a self-taught programmer and the technical content manager at Career Karma. He has experience in range of programming languages and extensive expertise in Python, HTML, CSS, and JavaScript. James has written hundreds of programming tutorials, and he frequently contributes to publications like Codecademy, Treehouse,, Afrotech, and others.

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