What Is A Computer Processor?

One of my older computers has been having a lot of trouble lately and it forced me to look into replacing parts if I want to keep using it. Of course, because of its age, parts are hard to come by, and I’ve considered just scrapping most of the computer. It did, however, cause me to take a rather closer look at the processor when I pulled it out of the motherboard. Even for a computer enthusiast, it’s not something you get to inspect up close all that often. Being that it’s so fragile, you typically don’t want to risk damaging it.

So what is a computer processor? A computer processor is known as a CPU or Central Processing Unit. Its primary function is to take data or instructions given to it from input and output devices, perform a set of arithmetic and logic calculations, then execute those instructions by communicating with the rest of the computer.

There’s a lot more to a CPU than just a single statement. It’s the central hub of your computer and has a complexity to match its importance. Without a processor, your computer would just be an idling hub of fans and lights. Nothing would ever work because there would be nothing to tell those components what to do!


Important Terms to Know About Computer Processors

Before we really dive into motherboards head first, there’s some important terms we need to go over first. Since a processor is the central hub of your computer, it has a lot of complicated parts. Some terminology you may never use in a typical conversation about processors, but knowing what they mean, especially if you intend to buy a new one, is especially helpful.

  • AMD – Short for Advanced Micro Devices. This is an American computer technology company that is widely known for their lines of CPUs.
  • Intel – Short for Intel Corporation. This is an American computer technology company that is widely known for their lines of CPUS.
  • CPU – Short for Central Processing Unit. This is the brain of the computer. Designed to take data fed to it and then use it to execute programs.
  • Core – This is terminology for referring to a fully complete processing unit. When a CPU was first invented, there was just one core. Modern day CPUs have at least two and sometimes even up to eight.
  • Hyper-Threading – An Intel processor specific feature that allows each CPU core to execute two instructions at the same time. This allows for certain cores to handle simpler work loads faster, while other cores process more complex instructions.
  • Clock – A specific wire inside the CPU that turns on and off at a rapid rate in order to keep all processes within the processor in sync.
  • Hertz (Hz) – A specific term for measuring “times per second”. For a CPU, this is the measurement of how many times the clock turns on and off. As an example, a 1 gigahertz processor has a clock that turns on and off 1 billion times per second.
  • L2/L3 Cache – This is an internal memory bank in the CPU itself. Not as robust as RAM, but faster. The bigger the cache on your processor, the faster it can perform.
  • Pins – These are the numerous tiny prongs sticking out of the bottom of a CPU. They connect into a CPU socket on a motherboard and allow information to be sent to and from the processor.
  • Instruction Set – This is an order of instructions that a CPU follows. Instruction Sets are unique to each processor.
  • Control Unit – This is a component inside the CPU. It communicates directly with the RAM and designates tasks for other components inside the processor.
  • ALU – Short for Arithmetic Logic Unit and another component inside the CPU. This is the component that performs all the mathematical operations inside the processor.
  • FE Cycle- Short for Fetch/Execute Cycle. This is shorthand for explaining the full processing cycle of a processor. Fetching data from the RAM, decoding it, then executing it.

Some of this terminology is a little more specific than others. If you find it a little confusing, don’t sweat it. A lot of processor terminology doesn’t have a practical use outside of knowing exactly how CPUs work in extreme detail. For the purposes of a broader overview, you don’t need to know much about that.

A Closer Look at Computer Processors

In 1971, Intel created the first central processing unit called the Intel 4004. A microprocessor that paved the way for electronics to shrink in size dramatically and would lead to personal computers to quickly become commonplace. This would also launch Intel into the stratosphere of holding a large majority of the CPU market share which continues to be true even to this day.

A computer’s CPU is dominantly considered to be the brain of the entire computer itself. It facilitates the means for all the other components to do the tasks they were designed to do, much like your muscles or organs do in your body. Without the brain, everything ceases to function. And just like an actual brain, a processor is a fragile piece of equipment that must be handled with extreme care.

Note: CPUs are not user serviceable. Do not ever attempt any processor repairs on your own. Please allow a professional to service this critical component of your computer!

When processors first came out, the completed product was called a core. A processor core is a complete set of data buses connecting a control unit and an arithmetic logic unit (ALU). These two components make up the core and are what carry out all the tasks a CPU needs to do.

As the processor was refined and iterated, more and more power and speed was demanded from the core. This would eventually lead manufacturers to create the multi-core processor. A multi-core processor is simply multiple complete processor cores within the same CPU, which allows for multiple tasks to be completed simultaneously and boosting the efficiency of the CPU itself.

In modern times, it’s a struggle to find a CPU that isn’t multi-core. Most will have a minimum of two cores, while many others will have four or even eight cores.

Before the breakthrough of multi-core processors, the frequency of the CPU was the only deciding factor of its speed. The frequency of a processor was measured in Hz or hertz which indicated how many tasks a processor could do a second. For example, a one gigahertz (1 GHz) could process one billion tasks a second.

In multi-core CPUs, the frequency is still an important indication of speed, but that frequency if applied to each individual core within the processor. For example, a four core CPU with a 1 GHz frequency would indicate that each of those four cores ran at that 1 GHz frequency. As you can guess, the more cores you have drastically multiplies the efficiency of the processor!

As a general rule, the fewer cores a CPU has, the faster it will tend to be. However, with fewer cores, the CPU will not be able to multitask as effectively. I personally always recommend to aim to get at least four cores if your budget allows. Four core processors are really common now and quite affordable on the low end. It’s a solid choice!

These days, you’ll find that 99.9% of all personal computer processors are made by two companies, AMD and Intel. Other companies produce processors of course, but these other companies (IBM, Qualcomm, Dell, Samsung, etc.) do not create CPUs designed for home PCs.

Computer enthusiasts will always have debates on which brand of CPU they prefer, Intel or AMD. However, the point of this article isn’t to convince you which side to choose in this ongoing argument. I will however, give you the brief overview of the differences between the two styles of processors from these companies:


Intel Advantages


  • A cooler running processor overall
  • A wider range of processors to choose from
  • Generally performs better pound for pound at the higher price end

Intel Disadvantages

  • All of their processors are more expensive when compared to an AMD equivalent
  • A lot of different socket types for their processors, making choosing a motherboard a challenge
  • Releases incremental upgrades for their processors every 1-2 years with very little differences


AMD Advantages

  • Less socket types so choosing a motherboard is easier
  • Performs better at the lower price end
  • Generally considered the better budget processor

AMD Disadvantages

  • Generally runs hotter than an equivalent Intel processor
  • Gets outperformed by Intel at the higher price range
  • Less range of CPUs to choose from

Some of these advantages and disadvantages are not necessarily going to pose an issue for many regular PC users. Both AMD and Intel make processors that work exceptionally well and unless you intend to push your computer to its limits, you won’t start running into any concerns with either brand of processors.

When you’re considering purchasing a processor, just keep your budget in mind and choose what would fit your needs best within that budget. You’ll also need to take care to make sure you’re buying a motherboard that has a socket type to support your CPU. If you’d like to know more about motherboards and socket types, I wrote an article about them here.

What Does a Computer Processor Do

A central processing unit facilitates the communication between all of your computer components via the electrical lanes on a motherboard. Data is sent to the CPU with instructions or a task and it uses its arithmetic logic unit (ALU) to discern what to do with the data it’s been sent. Once it understands the instructions, it will then transmit the data to the other components of your PC in order to carry out the task.

To be more precise, the processor runs on a FE Cycle, or Fetch/Execute Cycle. Meaning that whenever you use an input device on your computer like a keyboard or mouse, and tell your computer to do something, that sends a fetch request to the processor.

The CPU will then communicate with the RAM (Random Access Memory) on the motherboard in order to pull the information it needs to determine what needs to be done to carry out the instructions you just sent it. It will send the information through the ALU and store some of the data in the L2 or L3 cache (these are internal memory banks inside the CPU) in order to decide if this is the correct way to handle the task. If not it will pull another set of data from the RAM and repeat the process until its logic system has found the right set of steps. This is called the decode process.

After the CPU has determined the right process to carry out the task you requested from it, it will then communicate with the rest of the computer components to do that task. The end result will be transmitted through an output device like the speakers or monitor for you. This is the execute process.

In modern day computers, your processor is doing this FE Cycle billions of times a second. Even right now as you read this! It’s really amazing at how powerful a CPU truly is.

Processors and Hyper-threading

In recent years, Intel has begun to find more subtle ways to squeeze more processing power out of each core in their CPUs. This has lead to a development called hyper-threading. This is also called simultaneous multi threading (SMT) and exists on AMD processors as well, however Intel’s branding of their implementation of this design has become more or less the de-facto terminology. It just sounds good.

Hyper-threading is a technology that allows physical CPU cores to split into virtual cores. A dual core processor with hyper-threading will have four virtual cores, and a four core processor with hyper-threading will have eight cores, etc.

What this does, is allow the CPU to run two fetch/execute cycles through each core simultaneously and greatly boosting productivity. This allows for the processor to delegate some cores to handle multiple minor or background tasks at the same time while using other cores to handling more demanding tasks.

Hyper-threading requires an operating system and BIOS capable of handling it, but most modern motherboards have this covered by default and it’s a point of concern when considering a purchase!

Calculating Advantages (Conclusion)

Computer processors are fascinating components. They’re the sole purpose a personal computer can even exist and they become more and more powerful every few years. It’s hard to know where CPU development will head in the future, but one thing is for certain, they will be pushing the boundaries of computer performance constantly.

If you have any questions or comments please feel free to leave them below and I will do my best to respond directly!


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