images you see on your monitor are made of tiny dots called
pixels. At most common resolution settings, a screen displays
over a million pixels, and the computer has to decide what
to do with every one in order to create an image. To do this,
it needs a translator something to take binary data from the
CPU and turn it into a picture you can see. Unless a computer
has graphics capability built into the motherboard, that translation
takes place on the graphics card.A
graphics card's job is complex, but its principles and components
are easy to understand. In this article, we will look at the
basic parts of a video card and what they do. We'll also examine
the factors that work together to make a fast, efficient graphics
graphics card creates a wire frame image, then fills it in
and adds textures and shading.
Think of a computer as a company with its own art department.
When people in the company want a piece of artwork, they send
a request to the art department. The art department decides
how to create the image and then puts it on paper. The end
result is that someone's idea becomes an actual, viewable
Evolution of Graphics Cards
Graphics cards have come a long way since IBM introduced the
first one in 1981. Called a Monochrome Display Adapter (MDA),
the card provided text-only displays of green or white text
on a black screen. Now, the minimum standard for new video
cards is Video Graphics Array (VGA), which allows 256 colors.
With high-performance standards like Quantum Extended Graphics
Array (QXGA), video cards can display millions of colors at
resolutions of up to 2040 x 1536 pixels.
Creating an image out of binary data is a demanding process.
To make a 3-D image, the graphics card first creates a wire
frame out of straight lines. Then, it rasterizes the image
(fills in the remaining pixels). It also adds lighting, texture
and color. For fast-paced games, the computer has to go through
this process about sixty times per second. Without a graphics
card to perform the necessary calculations, the workload would
be too much for the computer to handle.
graphics card accomplishes this task using four main components:
motherboard connection for data and power
A processor to decide what to do with each pixel on the screen
Memory to hold information about each pixel and to temporarily
store completed pictures
A monitor connection so you can see the final result
Next, we'll look at the processor and memory in more detail.
Like a motherboard, a graphics card is a printed circuit board
that houses a processor and RAM. It also has an input/output
system (BIOS) chip, which stores the card's settings and performs
diagnostics on the memory, input and output at startup. A
graphics card's processor, called a graphics processing unit
(GPU), is similar to a computer's CPU. A GPU, however, is
designed specifically for performing the complex mathematical
and geometric calculations that are necessary for graphics
rendering. Some of the fastest GPUs have more transistors
than the average CPU. A GPU produces a lot of heat, so it
is usually located under a heat sink or a fan.