Work of Graphics Cards

Work of Graphics Cards

Most of us choose the video card as one of the first components when trying to purchase a computer, but it hasn’t been that long since we just considered the processor, memory, and hard drive while making that decision.

Let’s now look more closely at the video cards that we can get for a single computer when necessary.

Typical single graphics card appearance.

How Is the Screen Image Created?

The image on your monitor is frequently made up of small dots, which you may see if you look at it carefully enough.

The smallest component of an image is a group of these dots, or a pixel.

There are distinct color and intensity data for each pixel.

A pixel, in a broader definition, is the smallest area of the screen that may be independently studied.

The image on the screen is made up of thousands of these pixels.



We may claim that the resolution plays the biggest role in determining the image’s quality.

Resolution is expressed in terms of the number of pixels in both the horizontal and vertical directions (for example, 800600, 1024768).

The number of pixels in the image that can be independently inspected grows as the resolution does, as does the quality of the image.

Work of Graphics Cards

Since Windows 95 introduced the “scaleable screen objects” technology, the amount of screen real estate that can be utilized as the image quality improves.

The amount of pixels that make up the items on the Windows screen remains constant, regardless of the visual quality.

The available space on the desktop grows in direct proportion to resolution as the pixels get smaller with increasing resolution since the things occupy less space.

Naturally, the more pixels that must be checked and, therefore, the greater the processing effort necessary, the higher the resolution. This is also true for the quantity of memory needed to store the information for these pixels and the memory bandwidth needed for their transmission.

As a result, the performance declines.

The resolution you want to use should be supported by your graphics card, and even your monitor should be able to produce the necessary amount of pixels on the screen.

Shade Depth

We talked about the colors of the pixels themselves; red, green, and blue are the colors that the pixels can receive.

Here, the quantity of these hues is determined by the color depth.

Each pixel can acquire more colors as color depth rises, and the colors become more accurate.

Bits, which we briefly addressed in our essay about processors, are used to specify color depth.

The two possible values for a bit are 1 and 0.

28 = 256 combinations can be created from 8 bits when they are utilised.

Similar to this, 8-bit color depth allows for the use of 256 colors per pixel.

It takes 256 shades of each of the three colors—red, green, and blue—to make the image on the screen appear realistic and fool the human eye, increasing the number of bits per color from 8 to 24.

True Color is the name of this mode.

However, because they employ more modern video card picture memory, they need 32 bits to display pixels in this mode.

Alpha channel usage takes up the final 8 bits (which holds the transparency data of the pixels).

Green requires six bits in High Color (16-bit) mode, while blue and red each require five bits.

In this setting, there are 32 different intensities for blue and red and 64 different intensities for green.

Although there isn’t much of a difference in color fidelity compared to 32 bits, there is a performance gain over 32 bits due to the fact that 4 names per pixel require 2 bytes of memory (8 bits = 1 byte).

The 256 color (8 bit) mode could initially seem to have low color quality, but by employing this 8-bit in the most efficient way possible with the sole means to experience the color palette, the color quality is slightly improved.

The color scheme follows the following logic: A single color palette is made from the 256 colors that will be utilized, which are chosen from the 3-byte colors in the reality color mode.

Each program can select a color from a palette of 256 colors and use it.

As a result, the 8 bits we have are utilized to their fullest potential. For instance, utilizing two bits for red, three bits for blue, and four bits for green, vibrant colors can be created from the colors they have already obtained.

What does our graphics card do with the colors it cannot produce? We are familiar with the three most common color modes. Suppose our computer is configured to display 256 colors, but we only open a single 16-bit photo file.

In this instance, a single color that is almost identical to the color that cannot be generated by mixing several existing colors is developed, and the name of the color that must be produced includes this color.

Dithering is the term for this.

Of fact, the single painting created using the dithering technique is still inferior to the original.

Screen Interfaces

Previously, there was no universal standard for addressing pixels on the screen, which caused issues for both producers and programmers (and consequently end users).

To fix this problem
The creators established VESA, the exclusive group dedicated to standardizing video protocols (Video Electronics Standards Association).
By offering backward compatibility, VGA has enabled a constant improvement in image quality.

Let’s quickly review the standards, including those that came before VGA:

MDA (Hercules) stands for Monochrome Display Adapter, the graphics device found in the original 1981 IBM PC.

Only 256 eligible characters whose locations on the screen were known may be displayed.

In the past, the size of fonts that could be displayed on a single screen with 80 columns and 25 lines was likewise set, and visuals could not be displayed.

To save money on slots, IBM installed a single printer port in addition to these cards.

Graphics cards could interact with RGB monitors and examine the screen pixel by pixel using the CGA interface.

A single screen with a resolution of 320240 could produce 16 colors, but only 4 of them could be used at once.

There is only one 640×200 high image quality mode, but this mode can only display two colors.

Even with poor image quality, graphics may still be created.

This standard was in use for a long period, however occasionally the pixels would flicker and spots would show up on the screen.

EGA: The Enhanced Graphics Adapter came next, a few years following CGA.

Before IBM introduced the first PS/2 computers in 1987, these CGA to VGA cards were in use.

16 of the 64 colors generated might be used at once using an EGA monitor.

Additionally, it supported outdated CGA and monochrome displays and had great image quality and monochromatic modes.

The memory expansion cards were these cards’ lone novel feature.

These cards, which came with 64K memory, could be upgraded to 128K via a memory expansion card.

Additionally, a single 128K may be added using the IBM memory kit that was offered as an add-on.

Later, 256K memory became the standard for these cards when they were built.

PGA: After the target market it served, IBM introduced the Professional Graphics Array in 1984.

It retails for $5,000 and has an inbuilt 8088 CPU that allows it to conduct 3D animations for engineering applications and other scientific activities at 60 frames per second in 256 colors at 640480 resolution.

Due to its high price, it was removed from the market before it could spread greatly.

Graphics cards that adhere to the MultiColor Graphics Array standard, first released in 1987, achieved a significant technological advance that served as the only precursor to VGA and SVGA.

The IBM Model 25 and Model 30 PS/2 PCs had it integrated into the motherboard.

When used with a single compatible IBM monitor, it also supported all CGA modes, but since it utilized analog signals in place of TTL, it was not yet backwards compatible with earlier standards.

Only 1 and 0 values can exist in TTL (Transistor to Transistor Logic) logic because transistors open and close depending on the voltage level.

This limitation does not apply to analog signals.

The MCGA interface could output 256 colors thanks to the benefit of analog signaling.

The 9-pin monitor connector has been replaced with the 15-pin connection with this interface.

8514/A: Over time, this user interface, which IBM developed for the MCA bus, has attained high refresh rates.

Even though it shared a monitor with VGA, it operated differently from VGA.

The video card was receiving instructions from the computer, but it was also putting itself up to carry them out.

For instance, unlike VGA, the processor would not calculate the image pixel by pixel and send it to the video card when drawing a single circle on the screen.

In support of this, he claimed that the video card would generate a circle and that it could determine how many pixels to use to draw the circle on its own.

These advanced commands frequently deviated from the default VGA commands.

This standard was still in advance of its time of release, and VGA was still producing qualifying images, but it failed to gain any traction and left the market before it could take off.

IBM ceased manufacture and concentrated on XGA, which is identical but has more color options.

Since the introduction of XGA in 1990, MicroChannel platforms have adopted it as the norm.

The Video Graphics Array (VGA), introduced by IBM on April 2, 1987—the same day as the MCGA and 8514/A—became the desktop industry standard.

IBM has designed these chips as a single card that can be attached to the motherboard with a single 8-bit interface so that they can be used in classic computers, even if it merges these chips with the motherboard in its modern systems.

Different businesses continued to produce even after IBM ceased its operations.

A single palette of 262144 colors, chosen from, might be used by VGA to display 256 colors concurrently.

In a typical resolution of 640 x 480, 16 colors could be shown at once.

On black-and-white monitors with 64-color grayscale, it could also color warp.

Super VGA (SVGA) is a single, inclusive standard that applies to numerous cards, including the earliest SVGA cards and the most recent cards.
Device drivers for video cards along with SVGA started to make sense.

The drivers offered along with the cards allowed the operating systems to utilize all the functionality of the cards.

Millions of colors can be displayed with SVGA at various resolutions, however this is subject to the card’s and the manufacturer’s limitations.

Since SVGA is the sole notion shared by numerous businesses, its first restrictions were less stringent than those of traditional standards.

And VESA has created a single SVGA standard on top of it.

Programmers no longer need to create unique codes for each card thanks to the identification of a common single user interface known as VESA BIOS Extension.

Manufacturers initially made their cards compatible with these BIOS extensions with a single application that was included with the cards and ran after each boot since they did not want to embrace this user interface, but later integrated it into the BIOS of the cards.

With SVGA, a resolution of 800600 was accomplished.


Following SVGA, IBM XGA advanced to 1024768 resolution, and 12801024 with SXGA—the sole VESA standard—was the next stage.

After then, it was changed to 16001200 resolution using UXGA.

Only SXGA breaks the 4:3 resolution barrier; the ratio in this standard is 5:4.

A Single Graphics Card with the Basic Elements


The three main parts of a graphics card are the GPU, memory, and RAMDAC.

Graphics Processor: For modern cards, it wouldn’t be inaccurate to argue that the graphics processor is the only CPU used to build display calculations on top of the graphics card.

Recently, graphics processors have surpassed CPUs in terms of complexity and structure, and they are now the only CPUs with a function that is exclusively focused on images.

After that, they can complete three-dimensional processors without using the CPU at all.

Because of this, modern graphics processors are known as GPUs (Graphics Processing Unit).

Video Memory: Information pertaining to picture calculations is kept in this memory, which is found on top of the video card.

It functions similarly to your system’s main memory, with the exception that the image processor, not the CPU, is the addressee of this memory.

Prior to quicker and better image processors, video cards did not have distinct memory, but as time went on, they started to claim a small degree of independence from the system.

The capacity of the memory is just as crucial as how effectively the video card can employ its compression algorithms to use this memory.

RAMDAC (RAM Digital-to-Analog Converter): We previously discussed analog signals on monitors. In this case, RAMDAC (RAM Digital-to-Analog Converter) transforms data from the display memory into analog RGB (Red, Green, and Blue) signals and outputs them to the monitor.

Each of the three major colors used in the display has its own RAMDAC unit, which scans a predetermined number of image memory per second and converts the data inside into analog signals.

The speed at which RAMDAC can carry out this operation impacts the refresh rate of the screen.

The number of times per second that the image on the screen is refreshed is given in Hz at this speed.

For instance, if your monitor refreshes the image 60 times per second, it is working at 60 hertz (Hz).

As much as possible, I advise against lowering the screen refresh rate below 85 Hz because doing so could be bad for your eyes.

Naturally, how well-trained your eyes are will also play a role in this; although some eyes struggle to distinguish between 75 and 85 Hz, others are able to do so right away.

How many colors can be displayed at which resolution depends on RAMDAC’s internal design and functionality. LCD panels can access and utilise image data directly from the display memory, as opposed to RAMDAC, due to their inherent digital nature.

They do this by using a single certified connection known as DVI (Digital Video Interface).

In the future, the subject of “Why Do Monitors Work?” will be covered. In this article, we’ll go through it in more detail.

A BIOS is also included on graphic cards.

The major setup fonts and the video card’s operating parameters are saved here.

Additionally, while this BIOS boots up, it makes a few insignificant attempts to access the video card’s memory.


We’re going to dimension…

For 3D programs, some of us splurge on video cards.

Three primary phases go into creating a 3D single image:

A single virtual 3D region is produced.

The area of this environment that will be seen on the screen is chosen.

Every pixel will be seen as a cause in order to display the image as realistically as possible.

The virtual single 3D environment cannot be determined by just looking at one photograph of it.

Let’s begin by examining a tiny portion of reality.

As our 3D environment, let’s use our hand and the lone table underneath it.

When we touch the table with our hands, we can feel that it is hard.

The table does not break or allow our hand to pass through it when we strike it with our hands.

We cannot fathom the hardness of the table and the sensation it will provide to our hands with just those pictures, no matter how many times we look at pictures of this setting.

Virtual 3D environments are also.

unbiased in these
Each is artificial; the program provides them with all of its characteristics.
Programmers carefully consider each of these features when creating a single virtual 3D world. They also employ the right tools for the job.

On the screen, only one specific area of this 3D environment, created at a specific time, is visible.

Depending on how the world is defined, where you want to travel, and what you’re looking for, the image displayed on the screen changes.


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