www.makeuseof.com What Is a Graphics Card and How Does It Work?

You can't play your favorite video game without one, but how does a graphics card work?

Your computer has many components inside its case, each responsible for a different function. If you opened up your PC case right now, you'd likely find a motherboard, a CPU, some RAM, and a storage drive. Then, in some computers, you'd also find a graphics card, the bit of hardware responsible for creating images on your screen.

The graphics processing unit (GPU) is a vital piece of hardware. Without it, you wouldn't be able to play games, watch movies, or even flick through a Powerpoint presentation. So, what is a graphics card, and does it actually work?

What Is a Graphics Card?

So, when someone says "graphics card," they're referring to the GPU—the graphics processing unit. Like the motherboard in your computer, the graphics card is also a printed circuit board. It comes with a specific set of instructions to follow, and when it comes to standalone (known as discreet) GPUs, it'll also come with fans, onboard RAM, its own memory controller, BIOS, and other features.

While graphics cards can come in all different shapes and sizes, there are two main types:

A modern, discreet GPU will typically outperform an integrated GPU, but you do have to take CPU and GPU generations into consideration. If you're comparing hardware produced in the same era, the discreet GPU will win out. It simply has more processing power and more cooling available to process complex tasks.

Specific hardware varies between graphic card models, but most modern, discreet GPUs have the following components:

How Does a Graphics Card Work?

A graphics card is primarily responsible for rendering images on a display, be that photos, videos, games, documents, your regular desktop environment, a file folder, and anything else. All of these things, from tasks that require tremendous computing power, like a video game, to something we deem "simple" like opening a new text document all require the use of a graphics card.

Expanding on this a little, your graphics card maps the instructions issued by the other programs on your computer into a visual rendering on your screen. But, a modern graphics card is capable of processing a phenomenal number of instructions simultaneously, drawing and redrawing images tens or even hundreds of times every second to ensure whatever you're looking at, whatever tasks you're attempting to complete remains smooth.

So, the CPU sends information regarding what needs to appear on screen to the graphics card. In turn, the graphics card takes those instructions and runs them through its own processing unit, rapidly updating its onboard memory (known as VRAM) as to which pixels on the screen need changing and how. This information then whizzes from your graphics card to your monitor (via a cable, of course), where the images, lines, textures, lighting, shading, and everything else changes.

If done well, and the graphics card and other computer components aren't pushed to perform actions outside their capabilities, it looks like magic. The above description is very, very basic. There is a lot more going on under the surface, but that's a rough overview of how a graphics card works.

Who Makes Graphics Cards?

There are two big names when it comes to graphics cards: AMD and Nvidia. These two GPU powerhouses have dominated the market for decades, and although CPU giant Intel is stepping into the arena with its Arc Alchemist graphics cards, the names ringing out are AMD and Nvidia. Now, technically, AMD and Nvidia don't "make" graphics cards. They design them, then send them to a chip foundry for manufacturing, or license their designs to other brands like MSI, ASUS, Zotac, Palit, and so on, who do the same.

But, we don't want to quibble, so let's stick to talking about AMD and Nvidia. If you open a website today and attempt to buy a new graphics card, you'll end up with a design from one of these two. This begs the question, does it really matter which GPU you buy?

How to Choose a Graphics Card

At the time of writing, the world is still emerging from the global chip shortage that contributed to GPU (and other PC hardware) prices rocketing. But as prices slowly begin to fall back to respectable levels (don't hold your breath!), you might wonder how you go about choosing a graphics card for your machine.

There are a few things to take into account:

Everyone Needs a Graphics Card

Remember, graphics cards and GPUs aren't limited to desktop computers. They're found in your smartphone, your tablet, your smartwatch, your PS5, your Xbox Series X, and everything else that displays a visual interface. The technology isn't always as advanced, but everything with a screen needs a way to show you information. Now you know where it comes from.

Gavin is the Junior Editor for Technology Explained, a regular contributor to the Really Useful Podcast, and a frequent product reviewer. He has a degree in Contemporary Writing pillaged from the hills of Devon, and more than a decade of professional writing experience. He enjoys copious amounts of tea, board games, and football.

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