how graphics card works

A graphics card is a printed circuit board that oversees the output of the graphical images on the display screen.

Graphics cards have come a long way since when they were invented back in 1981. Monochrome Display Adapter (MDA) was the first graphics card that could only display texts of white or green on a black background.

Today, the top-of-the-line graphics cards can display millions of colors at comparatively astounding resolutions.

By monitoring the display of your computer screen, the graphics cards have a crucial part to play in your computer system but the question is, how are the graphics cards able to do what they do?

In our guide below, we have explained the whole working principle of a graphics card by giving you an in-depth look at all of its key components, the difference between integrated and dedicated graphics cards, and more.
So, let’s get started!

How does a Graphics Card work? Everything that You Should be Aware of!

The operation of a graphics card is a complex process but if we streamline it, it is something like this:

First, the CPU sends out information related to an image, in the form of binary data, to the graphics card.

To create a 3-D image out of this data, the graphics card first creates a wire mesh out of straight lines. Then, it fills out the remaining pixels and adds lighting, color, and texture to the image. Finally, it transfers the image to the monitor via a cable for display.

For heavy games and software, this process is almost sixty times as quick. That explains why without a graphics card, a computer would simply crumble while such games and software.

A graphics card makes use of the monitor and the motherboard for its work. On the card itself, you can find a GPU (the processor) and VRAM.


A graphics processing unit (GPU) is the processor of a graphics card that carries out graphics rendering through complex mathematical and geometric calculations. In other words, it is the brain of the graphics card.

Due to the nature of its task, a GPU dissipates a lot of heat which is why it is usually located under a heat sink or a fan.

The two mainstream manufacturers of GPUs in the market are AMD and Nvidia. Each of these two manufacturers applies special techniques in their GPUs to tweak the application of colors, shading, textures, patterns and hence improve the overall performance of the GPU.

For instance, to boost the image quality, the processors use Full scene anti-aliasing (FSAA) and Anisotropic filtering (AF). FSAA smooths the edges of the 3-D objects while AF makes images look sharper.


As images are being continuously created by the GPU, they need someplace to be stored. This is where the memory/VRAM of your graphics card comes into play.

A higher memory capacity of the VRAM means that more data can be copied to and from the VRAM in a second and hence, more images can be stored.

Apart from storing the image’s each pixel, its color, and its location on the screen, VRAM also acts as a frame buffer. This means that it only displays the images on the screen when prompted.

Whenever you try to view an image, the VRAM sends that specific image to the digital-to-analog converter (DAC), also known as the RAMDAC. The DAC converts the image into an analog signal and conveys it to the monitor through a cable to be displayed on the screen.

In the graphic cards with multiple RAMDACs, this whole process goes on a lot faster. On top of that, it all can happen on more than one monitor!

PCI and Other Connections

Graphics cards are connected to your computer system through the motherboard. The motherboard not only supplies power to the graphics card but also lets it communicate with the CPU.

However, the advent of the powerful graphics card in the current era means that the power supplied to them by the motherboard is simply not enough.

To tackle this problem, the graphics cards now have a direct connection with the power supply as well and they are connected to the motherboard through one of the three interfaces:

  • Peripheral component interconnect (PCI)
  • Advanced graphics port (AGP)
  • PCI Express (PCIe)

Amongst these, PCIe is the latest and the fastest. Also, it supports two graphics cards in one computer.

Furthermore, most of the graphics cards have two monitor connections. You will find an HDMI port and a Display Port in modern cards. Previously, the DVI connector, which supported LCD screens, and the VGA connector that supported CRT screens was common.

graphics card connectors

However, if your graphics card has incompatible connections, you can use an adapter if you want to solve the problem in a pinch.

There are also some graphics cards with dual-head capability that makes it possible to divide the display between two monitors.

Additionally, a few of the graphics cards out there allow you to make connections to TV, Analog video cameras, and Digital Cameras as well.

Frame rate

Frame rate or frames per second (FPS) determines how many complete images a graphics card can display in a second. The greater the FPS, the better is the graphics card.

The frame rate consists of the following two components:

  • Triangles/Vertices per second – It defines how quickly a GPU can process the 3-D images which are usually in the form of triangles and polygons.
  • Pixel fill rate – It defines how quickly a GPU can rasterize an image.

Integrated and Dedicated Graphics Cards

In a PC, the CPU generally has an integrated graphics card/video card which helps the computer in tasks related to 2-D imaging, web-surfing, reading emails, etc.

However, when it comes to activities like 3-D image processing and fast-paced video games, apart from this integrated graphics card, you will need to plug in a dedicated graphics card too.

A dedicated graphics card serves as an extra pair of hands to help your PC handle the high-end software and video games.

The type of dedicated graphics card you should get depends on your requirement and budget. Now that you have a good understanding of how a graphics card works, you will have a much easier time choosing the best one for yourself!

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