Graphics Card Basics

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 picture.

The four main components of a graphics card are connections for the motherboard and monitor, a processor, and memory.

A graphics card works along the same principles. The CPU, working in conjunction with software applications, sends information about the image to the graphics card. The graphics card decides how to use the pixels on the screen to create the image. It then sends that information to the Monitor through a cable.

The 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.

Dedicated Graphics Cards

The most powerful class of GPUs typically interface with the motherboard by means of an expansion slot such as PCI Express (PCIe) or Accelerated Graphics Port (AGP) and can usually be replaced or upgraded with relative ease, assuming the motherboard is capable of supporting the upgrade. A few graphics cards still use Peripheral Component Interconnect (PCI) slots, but their bandwidth is so limited that they are generally used only when a PCIe or AGP slot is unavailable.

A dedicated GPU is not necessarily removable, nor does it necessarily interface with the motherboard in a standard fashion. The term "dedicated" refers to the fact that dedicated graphics cards have RAM that is dedicated to the card's use, not to the fact that most dedicated GPUs are removable. Dedicated GPUs for portable computers are most commonly interfaced through a non-standard and often proprietary slot due to size and weight constraints. Such ports may still be considered PCIe or AGP in terms of their logical host interface, even if they are not physically interchangeable with their counterparts.

Multiple cards can draw together a single image, so that the number of pixels can be doubled and antialiasing can be set to higher quality. If the screen is parted into a left and right, each card can cache the textures and geometry from their side (See Scalable Link Interface (SLI) and ATI CrossFire).

Integrated graphics solutions

Integrated graphics solutions, or shared graphics solutions are graphics processors that utilize a portion of a computer's system RAM rather than dedicated graphics memory. Such solutions are cheaper to implement than dedicated graphics solutions, but are less capable. Historically, integrated solutions were often considered unfit to play 3D games or run graphically intensive programs such as Adobe Flash^[ (Examples of such IGPs would be offerings from SiS and VIA circa 2004.) However, today's integrated solutions such as the Intel's GMA X3000 (INTEL G965), AMD's Radeon X1250 (AMD 690G) and NVIDIA's GeForce 7050 PV (NVIDIA nForce 630a) are more than capable of handling 2D graphics from Adobe Flash or low stress 3D graphics However, the aforementioned GPUs still struggle with high-end video games. Modern desktop motherboards often include an integrated graphics solution and have expansion slots available to add a dedicated graphics card later.

As a GPU is extremely memory intensive, an integrated solution finds itself competing for the already slow system RAM with the CPU as it has no dedicated video memory. System RAM may be 2 GB/s to 12.8 GB/s, yet dedicated GPUs enjoy between 10 GB/s to over 100 GB/s of bandwidth depending on the model.

Older integrated graphics chipsets lacked hardware transform and lighting, but newer ones include it.

TOP 10 GRAPHICS CARDS

TOP 10 GRAPHICS CARDS

1. Nvidia GeForce 9800 GTX
Similar in many ways to the GeForce 8800 GTS, the 9800 GTX is near the top-end of the GeForce 9 series from Nvidia. The 9800 GTX typically comes with 512 MB of memory, and it's the fastest single GPU solution available in the $300 price range. The 9800 GX2, which has 2 GPUs on board, is even more powerful, but given the price it's difficult to recommend over other SLI configurations. The 9800 GTX isn't a dramatic leap ahead of GeForce 8800 cards, but its competitive pricing has made it very attractive. Note that these cards can be almost 27 cm long, so it could be difficult, if not impossible, to squeeze them into some computer cases.

2. Nvidia GeForce 8800 GT
Despite having one less letter after its name, the GeForce 8800 GT was the last card released in the 8800 series. Nvidia made several improvements to the chipset with this edition. It consumes less power than other 8800 chips and it also included integrated HD video decoding. The 8800 GT performs better than the 8800 GTS on some benchmarks, and it almost catches the much more costly 8800 GTX, making it more appealing than both the GTS and the GTX. The 8800 GT offers high-end performance at a reasonable price, making it one of the most popular cards on the market right now.

3. Nvidia GeForce 9600 GT
The first GeForce 9 cards arrived in February 2008, beginning with the 9600 GT, which is aimed at the mid-range market. Although it has only half as many stream processors as the 8800 GT, it is a powerful chipset for the money, and it's putting downward pressure on video card prices across the board. These cards typically have 512 MB of memory and a core clock speed of 650 MHz, but there are overclocked versions available. At less than $200, they're also a solid option for people considering an SLI setup.

4. ATI Radeon HD 3870
ATI cards are starting to look a lot more attractive again with the release of the HD 3800 series, their latest round of DX10 video cards. The HD 3870 has a core clock speed of 775 MHz and comes with 512 MB of DDR4 memory. Using a 55 nm process has allowed them to produce a chip with performance that rivals their former champ, the HD 2900 XT, at a far lower cost. Although the Radeon HD 3870 sells for about the same price as a GeForce 8800 GT, is a bit slower, but it's still a good gaming card that won't cost you a fortune.

5. ATI Radeon HD 3850
Very similar to the HD 3870, the HD 3850 is clocked a little slower than its sibling, and it now comes with either 256 MB or 512 MB of memory. It's a respectable performer, falling only a few frames per second behind the GeForce 8800 GTS on some benchmarks. Recent price drops have made it a great deal for a mid-range GPU, and probably the best value of all ATI-based gaming cards at the moment.

6. Nvidia GeForce 8800 GTS
The GeForce 8800 GTS is a toned-down version of the 8800 GTX. They run at slightly slower clock speeds, have a few less shader units, and are available with several different memory configurations. These cards offer solid game performance, but simply put, the 512 MB 8800 GT is a better buy right now unless you come across a GTS that's significantly reduced in price.

7. Nvidia GeForce 8600 GTS
The GeForce 8600 is a mid-range chipset with DirectX 10 compatibility, so far available in GT and GTS flavors. The GTS has the higher clock speeds of the two. They use a 128-bit memory interface, which is a bit disappointing given that many previous-generation cards have 256-bit memory. Nevertheless, their performance in DX9 is respectable, even if they can't quite catch some of the DX9 cards in this price range. If you want the option to move to DX10 in the near future and don't have much money to spend, the 8600 GTS is worth a look.

8. ATI Radeon X1950 Pro
A step down from the X1950 XT, the X1950 Pro is clocked slower and has fewer pixel shader units, but it will handle most games currently available with ease. These cards usually come with 256 MB of GDDR3, rather than the 512 MB of GDDR4 on XTX models. Although the X1950 is a DX9 chipset, it still performs well next to some of the DX10 cards on the market. It hasn't come down in price quite as much as the competition, and it will likely get hard to find these cards soon.

9. ATI Radeon HD 2600 XT
There are 256 MB and 512 MB versions of the Radeon HD 2600 XT, and you may want to look for one that uses GDDR4 memory rather than GDDR3. The performance is on par with GeForce 8600s using the latest drivers, and most of these cards need only a single-slot with no additional power connector. Like all Radeon HD cards, it features hardware processed High Definition Blu-ray and HD DVD video.

10. Nvidia GeForce 8600 GT
Now within the reach of "budget" game systems, the GeForce 8600 GT aims to make DX10 cards mainstream. As usual, the primary difference between the GT and GTS models is that the GT runs at slower clock speeds. While a Radeon X1950 Pro will outperform them in most DX9 games, these are still decent cards for the money. They overclock quite nicely and they've gotten remarkably affordable in recent months.