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Your Computer's Video Card
This guide explains what a video card is, and covers everything from the basics to fairly detailed technical material. This guide will help you select the video card that's best for you. The topic of buying a card on eBay is also addressed.
A video card is a small, removable, expansion card with a printed circuit board, often red or green, with electronic components on its surface, as well as a fan, in some cases. It is usually sized about 6" long by 3.5" high, the size of a standard PCI card, though different sizes exist as well. A video card will always have at least one video output connector on its 1/4" wide metal face, with prongs on its bottom to interface with your machine by fitting into a slot inside the case, usually on the main motherboard.
Sometimes a video card is called a graphics card, a "V card" or "VC", display adapter, video adapter, gaming card, graphics adapter, and video display board. Nowadays, many refer to their video card simply by brand name or model.
Where Is It?
Some computers have a built-in video processor. These "all-in-one" machines come with an on-board video system. On such machines, the display adapter is not removable. With such computers, you don't NEED a video card, but you can still add one, and in fact may want to.
Some computers do not have built-in video display adapters. In order to view the display output, you must connect a video card.
How Do I Remove the Card?
On-board video display adapters are not removable, though they may be disabled, or used in conjunction with one (or more) add-on video cards.
For machines using PCI and PCI-Express, simply remove the screw located at the top of the card, which locks the card in place. Remove the screw, then pull up gently until the card's prongs separate from the slot underneath on the motherboard. (Power down and unplug the machine first!) AGP slots also have a locking tab on the bottom that keeps the card sitting correctly in the slot.
Card Types
Video cards are "plug and play" devices; your computer can auto-sense the card, and find the correct resources for it, either from your hard-drive, floppy, or CD.
PCI slot-type, PCI-Express (PCI-E), and AGP video cards are NOT interchangable; each is a different size with unique specifications. Check your computer user guide to see what type of slots are on your motherboard. NEVER force a card into a slot!!
PCI
This is the same slot used by most sound cards, modems, and network cards.
Older video cards were made to connect to the computer via the PCI slot (Peripheral Component Interconnect standard). The PCI standard specifies a distinct way of attaching peripheral devices to the computer's motherboard.
The PCI bus runs at 33.33 MHZ, transferring 133 MB per second with a 32-bit bus width, while PCI 2.2 passes signals at up to 66 MHZ with a maximum transfer rate of 533 MB per second. PCI-X exchanges data at 133 MHZ, with a transfer rate that cannot exceed 1,066 MB per second, PCI-X 2.0 transfers data at 266 MHZ, with a peak speed of 2,133 MB per second.
Mini PCI is a smaller form factor utilizing PCI 2.2, and has been built primarily for laptops.
PCI-Express
PCI-Express, also known as PCI-E and 3GIO ("3rd Generation" Input/Output) is a similar type of computer bus to the older PCI standard. The difference is that PCI-Express has a faster bus, utilizing a more speedy communications protocol. From the software's point of view, PCI-E is exactly the same as PCI. It is completely backwards-compatible.
(That means that programs designed to run on older PCI video can also be used with PCI-Express. This does not mean that a PCI-Express card will working a PCI slot, or vice versa!)
AGP
AGP stands for Accelerated Graphics Port, or Advanced Graphics port. AGP is a high-speed connection for attaching video cards, (no other type of cards), to the motherboard. Many computer have one AGP slot as well as a multiple PCI slots. The AGP slot is usually brown in color and is set a few inches further forward from the rear of the machine than the PCI card slots.
AGP accelerates 3D computer graphics. There are four types of AGP: 1x, 2x, 4x, and 8x. AGP 1x runs at 66MHz, 2x is double-pumped to 133MHz, 4x is quad-pumped at 266 MHZ, and 8x runs at a blinding 8-strobed 533 MHZ.
AGP Pro
These cards require more power than the standard AGP graphics cards. The card itself is sometimes longer than the standard AGP 1x-8x cards, but still work with a standard AGP video slot.
How Does the Video Display Adapter Work?
The video card permits connection of a monitor, TV, LCD TV, HDTV, or projector to your computer, allowing many different types of display output.
The card communicates with the computer's CPU over a bus, a bunch of wires connecting the two. Video cards have their own processor, often called the Graphics Processing Unit or GPU. It therefore is a computer within a computer. Cards have their own memory and RAM chips.
The graphics processor creates a video output, using complex mathematical algorithmic and geometric calculations, out of the digital signal it receives from the CPU which sends electrical signals over the data bus. The memory chips are used to store information about the video image on the screen and for storing figures (temporarily-for only split-seconds) needed for calculations for animation and other advanced graphics features.
Cooling & Power
The graphics processor, and sometimes even the memory, is covered by a heatsink, since the GPU has many more transistors than the average CPU. These produce lots of heat.
The heatsink is a piece of metal coming off of the card at a 90 degree angle. This helps to dissipate heat, conducting it through the metal fins, off of, and away from, the surface of the card.
Newer cards that require more power often have a fan as well. Some cards require a direct connection to the computer's fan power leads because they draw so much power. Always check that your computer's power supply is rated ABOVE the amount needed for the card. The minimum number of watts needed will be printed either on the card itself, or in the user's manual.
On-screen images are comprised of millions of tiny dots, called pixels. The video card decides whether or not those pixels are turned on or off, resulting in an image with color, tone, and contrast.
Modes (See "Monitors Guide" for more information)
There are various display standards, or display modes. They specify resolution (width and height of pixels), color depth (measured in bits, and determines the maximum number of on-screen colors), and refresh rate (expressed in hertz-the number of times per second that the screen is redrawn per second).
Aspect Ratio & Wide-Screen
This figure is arrived at by taking the total displayed width by the height, and is usually expressed as a ratio, or fraction (x.y) Traditional TV and monitor screens have an aspect ratio of 4:3, or 1.33:1.
High Definition Television sets (HDTV) use an aspect ratio of 16:9, or 1.78:1, because such screens are longer, in proportion to their overall height.
The "big screen" theaters use an aspect ratio of 2.39:1, or 1.85:1, or 1.37:1. Recall that when you go to the movies, the screen is much longer, compared to its height, than a standard TV screen.
Most newer video cards support multiple aspect ratios. If they do not, then they cannot support Wide-Screen formats.
Display Device Support
Older cards may only have one output. This can easily be used with flatscreen monitors, with a low-cost adapter. Using more advanced display hardware, such as HDTV, requires a special connector, and a simple adapter will not work. Be sure to note the video outputs that a card has, so that you buy a card that is compatible with your video display(s).
Inputs
Some video cards have S-Video connectors or standard composite connectors video inputs that allow video capture from a TV or other video source, such as a camcorder or VCR.
Multiple Displays
Some video cards support more than one display output. That means the video card can send different signals to each display device. (Cards with multiple outputs may also be used to send the same image to multiple video outputs at the same time.)
Whether your card features one or more outputs, most computers will accept multiple video cards. Therefore, you can have a computer system with multiple independent video outputs, each displaying different images all at the same time.
Which is Best Suited for My Needs?
That depends on your application.
Dedicated Gaming
This is the market segment driving the sales of video cards; every family has at least one gamer who spends a sizable amount of time playing the newest hits, nonstop! For a card meeting such a hardcore gamer's needs, you will have to invest in a newer V card.
New games are optimized to run on the newest technology, enabling dazzling true-color backgrounds, smooth animation, realistic shadows and other special effects. If you're planning to buy that special gamer in your life a cool birthday present, be sure to select a card that's made for gaming.
Graphic Design/CAD
This is another area of use that requires a high-end card. Amination software, as well as Computer Aided Design (CAD) programs with 3D panoramic views, require a video card with ample power.
Family Computer
The family computer probably sees the most diverse activity: Browsing the web, running streaming video, playing games, and more. Multi-media home computers require a video card that can do all this. The "All-in-Wonder" ATI card combines the best of all multimedia features, at an entry-level price.
A brand-new top-of-the-line advanced 3-D graphics card may be overkill, especially if you don't have a gamer in the family, playing the newest-latest titles.
Office
Your office computer doesn't run programs using high-end graphics or 3-D animation, right? In fact, your office machines may be fine running in monochrome mode. Word processing, spreadsheets, and other programs do not require anything special.
Therefore, an older model or newer low-end graphics card would suffice. A computer used to browse the web may need something a bit more powerful. If you are planning to use the machine to work on multimedia presentations, you'll need something better still.
Just don't go overboard; match the application with the card. Outfitting every one of your office's computers with the fastest video card on the market would be an unwise allocation of resources.
Color Depth
Color Depth refers to the number of bits-per-pixel (bpp). A higher color depth lends a wider range of varying tones and hues. One-bit color is monochrome, as individual bits on the screen can only be on or off.
Super VGA, popular during the 1990s, featured 8-bit color. Truecolor is 24-bit, with eight bits each representing red, green, and blue. The total number of possible colors using TrueColor is 16.7 million. Some video cards can display modes that surpass the TrueColor standard.
Graphics Processing Unit
The Graphics Precessing Unit, or GPU (and less frequently called the Visual Precessing Unit or "VPU") is the "brain" of your video card. The GPU controls how your video card works, and renders 3-D graphics, as well as static screen images. The GPU chip also handles streaming digital video. This is the core of your video card. The GPU uses a multitude of transistors to perform lighting-fast calculations.
Clock Speed & Memory
The cards clock speed, or "core speed", is measured in MHZ (and Ghz) and notes how fast the card's GPU chip processes digital instructions. A faster GPU results in better performance, generally.
The RAM, or memory, is a number that represents the total free amount of space available on the card for the GPU to use as the frame buffer for the image on the screen, as well as a work space for the calculations that the GPU needs to perform.
The memory used today is often called DDR2 or DDR3. Generally, the more video RAM on the card, the better. The RAM speed is measured in MHZ (and Ghz). Having a good amount of RAM is good, but having memory that runs faster is even better.
Bus Width
The bus is the connection between the video card and the CPU. Some cards support 256-bit data transfer. That is like having 256 individual channels to transceive data between the GPU and CPU. Other cards have only a bus only 128 bits wide. A wider bus allows speedier communications between the CPU and GPU.
Pixel Pipes
A video card often has a fixed number of pixel pipelines, or number of processing paths that can generate one pixel (per pipe) per clock cycle. Each pixel pipelines is handled in parallel, simultaneously sending output to the video display(s). More pixel pipelines means 3D images will be rendered faster.
TMUs
Texture Mapping Units, or TMUs refer to the number of textures that may be applied during a single clock cycle. The video card uses program data to derive a color value for a given pixel, so that real-time calculations can create realistic polygonal textures, first creating a wire frame image, and then rapidly filling the frame with correct texture and shading.
Direct X
This refers to APIs (Application Programming Interfaces) that are used for games, usually for Windows. These include DirectDraw, DirectPlay, DirectSetup, DirectMusic, DirectXmedia, DirectSound3D, Direct 3D, and DirectInput APIs. These modules help make it easier for the CPU to communicate with the video card.
Making Sense of An eBay Ad
"PowerColor ATI Radeon 9800 256MB AGP 8X 128BitDirectX 9"
This was an actual video card sold on eBay recently. Let's see what all the numbers mean. Powercolor is the brand name. ATI tells us that the card is based on ATI's design. Radeon 9800 tells us the series and model. 256 MB refers to the amount of video ram on the card. AGP 8X tells us that the maximum AGP speed is 8X. 128Bit means that the bus is 128 bits wide. Direct-X 9 tells us that's the latest version that the card will support.
Pay careful attention to the details of eBay ads. The title will provide you with some general information, but for the specific details, check the listing carefully. If you are unsure about something, don't hesitate to contact the seller while the auction is still running. And remember to consider insuring the item, if the seller offers it.
Brands
Some generic brands will work just as well as the more well-known names, however you may want the reliability of a known performer. Some respected brand names include Powercolor, ATI Technologies, NVIDIA, Chaintech, Leadtek, MSI, Rosewill, XFX/Pine technology, and ASUS.
Different cards have different cooling systems, memory speeds, manufacturers, and graphics processor speed and type. When comparing cards, take careful notice of the technical specifications. Be sure that the card you buy meets or exceeds your present needs.
ATI or Nvidia?
ATI, or Array Technologies Incorporated (TSX: ATY, NASD: ATYT) is a North American graphics card developer and manufacturer. Further, some third parties have arranged to manufacture ATI's proprietary design, but often using their own modifications or enhancements.
NvidIA Corporation (NASD: NVDA) is ATI's major competitor in the high-end graphics and gaming card lines. NVIDIA makes its own series of cards, known as the GeForce.
There is an ongoing debate among gamers regarding which brand is best, however, there is no clear answer. It seems to be a personal preference.
Pricing
Video cards range in price. You can expect to pay from a few dollars to hundreds of dollars, depending on the specifics of the card. To get an approximate idea of how high auctions usually run for a card that you are interested in bidding on, check out the completed listings on eBay. Then, you can see what the card sells for, on average, and you'll have a rough estimate of how much you will have to spend to have a reasonable chance at a successful bid.
How Long Will My Video Card Stay Current?
You can use your card for years, however the newest graphics-intensive games demand the fastest cards. Therefore, if your goal is to play the latest games with the absolute best graphics possible, then you need to upgrade every year or so.
You can easily keep a card for a few years, because new games will often work on older cards, though the graphics will not display as well as a newer, faster card would. For some non-graphics applications, an older card is sufficient, and usually remains so for quite a while.
Used Cards
You can buy used cards on eBay. Some are used, others refurbished. Sometimes these cards have warranties. New cards are also widely sold on eBay.
Drivers
Most video cards require the use of special files, called drivers, as well as additional software. When buying a video card new, there will likely be a CD with software bundled with the video card. Buying a card used on eBay, and you may, or may not, also receive the drivers.
If the drivers and/or additional software is not included, you can usually go to the website of the company that makes the card and download the drivers for free. Note that drivers and other video card software are often updated to correct problems, add features, and improve performance. Check online for updates, and download and install as needed.
Be sure that the software that you are downloading will work with your operating system! If you are running Windows 98, for instance, you are limited in that many newer video cards do not offer software or drivers that will run under your operating system. Check before buying, as a card without the proper drivers or other software will not work at all!
Overclocking/Flashing
Overclocking refers to resetting the default parameters of the video card. The clock speed of the Graphics Processor and memory on the video card may be sped up. This requires more voltage to the card, and more voltage creates more heat.
Without a good knowledge base, overclocking is not recommended. Good ventilation is a must! If a card runs too hot for too long, it will not work properly any longer. This also reduces the total number of useful hours the card will perform before eventually failing.
Flashing refers to replacing the card's firmware with a newer version. Some cards can be upgraded to run like other more feature-rich cards, higher in the series. This is another dangerous procedure, and must be done with extreme care. It is not recommended unless you know exactly what you're doing. A card that has been improperly flashed, or flashed with the wrong firmware will not work.
Benchmark Testing
Benchmark programs assess a video card's performance, after checking the card's capabilities. Many benchmark programs will calculate a score, or list a set of parameters detailing the card's performance. Some such programs include 3DMark, 3DBench, WinMarks, WITS, and WinStones.
Common metrics used are "polygons-per-second" and the "fill rate". A higher fill rate allows higher resolutions and more colors at a higher refresh rate.
© Copyright H. Miller 2oo6 - 2007, All Rights Reserved
This guide explains what a video card is, and covers everything from the basics to fairly detailed technical material. This guide will help you select the video card that's best for you. The topic of buying a card on eBay is also addressed.
A video card is a small, removable, expansion card with a printed circuit board, often red or green, with electronic components on its surface, as well as a fan, in some cases. It is usually sized about 6" long by 3.5" high, the size of a standard PCI card, though different sizes exist as well. A video card will always have at least one video output connector on its 1/4" wide metal face, with prongs on its bottom to interface with your machine by fitting into a slot inside the case, usually on the main motherboard.
Sometimes a video card is called a graphics card, a "V card" or "VC", display adapter, video adapter, gaming card, graphics adapter, and video display board. Nowadays, many refer to their video card simply by brand name or model.
Where Is It?
Some computers have a built-in video processor. These "all-in-one" machines come with an on-board video system. On such machines, the display adapter is not removable. With such computers, you don't NEED a video card, but you can still add one, and in fact may want to.
Some computers do not have built-in video display adapters. In order to view the display output, you must connect a video card.
How Do I Remove the Card?
On-board video display adapters are not removable, though they may be disabled, or used in conjunction with one (or more) add-on video cards.
For machines using PCI and PCI-Express, simply remove the screw located at the top of the card, which locks the card in place. Remove the screw, then pull up gently until the card's prongs separate from the slot underneath on the motherboard. (Power down and unplug the machine first!) AGP slots also have a locking tab on the bottom that keeps the card sitting correctly in the slot.
Card Types
Video cards are "plug and play" devices; your computer can auto-sense the card, and find the correct resources for it, either from your hard-drive, floppy, or CD.
PCI slot-type, PCI-Express (PCI-E), and AGP video cards are NOT interchangable; each is a different size with unique specifications. Check your computer user guide to see what type of slots are on your motherboard. NEVER force a card into a slot!!
PCI
This is the same slot used by most sound cards, modems, and network cards.
Older video cards were made to connect to the computer via the PCI slot (Peripheral Component Interconnect standard). The PCI standard specifies a distinct way of attaching peripheral devices to the computer's motherboard.
The PCI bus runs at 33.33 MHZ, transferring 133 MB per second with a 32-bit bus width, while PCI 2.2 passes signals at up to 66 MHZ with a maximum transfer rate of 533 MB per second. PCI-X exchanges data at 133 MHZ, with a transfer rate that cannot exceed 1,066 MB per second, PCI-X 2.0 transfers data at 266 MHZ, with a peak speed of 2,133 MB per second.
Mini PCI is a smaller form factor utilizing PCI 2.2, and has been built primarily for laptops.
PCI-Express
PCI-Express, also known as PCI-E and 3GIO ("3rd Generation" Input/Output) is a similar type of computer bus to the older PCI standard. The difference is that PCI-Express has a faster bus, utilizing a more speedy communications protocol. From the software's point of view, PCI-E is exactly the same as PCI. It is completely backwards-compatible.
(That means that programs designed to run on older PCI video can also be used with PCI-Express. This does not mean that a PCI-Express card will working a PCI slot, or vice versa!)
AGP
AGP stands for Accelerated Graphics Port, or Advanced Graphics port. AGP is a high-speed connection for attaching video cards, (no other type of cards), to the motherboard. Many computer have one AGP slot as well as a multiple PCI slots. The AGP slot is usually brown in color and is set a few inches further forward from the rear of the machine than the PCI card slots.
AGP accelerates 3D computer graphics. There are four types of AGP: 1x, 2x, 4x, and 8x. AGP 1x runs at 66MHz, 2x is double-pumped to 133MHz, 4x is quad-pumped at 266 MHZ, and 8x runs at a blinding 8-strobed 533 MHZ.
AGP Pro
These cards require more power than the standard AGP graphics cards. The card itself is sometimes longer than the standard AGP 1x-8x cards, but still work with a standard AGP video slot.
How Does the Video Display Adapter Work?
The video card permits connection of a monitor, TV, LCD TV, HDTV, or projector to your computer, allowing many different types of display output.
The card communicates with the computer's CPU over a bus, a bunch of wires connecting the two. Video cards have their own processor, often called the Graphics Processing Unit or GPU. It therefore is a computer within a computer. Cards have their own memory and RAM chips.
The graphics processor creates a video output, using complex mathematical algorithmic and geometric calculations, out of the digital signal it receives from the CPU which sends electrical signals over the data bus. The memory chips are used to store information about the video image on the screen and for storing figures (temporarily-for only split-seconds) needed for calculations for animation and other advanced graphics features.
Cooling & Power
The graphics processor, and sometimes even the memory, is covered by a heatsink, since the GPU has many more transistors than the average CPU. These produce lots of heat.
The heatsink is a piece of metal coming off of the card at a 90 degree angle. This helps to dissipate heat, conducting it through the metal fins, off of, and away from, the surface of the card.
Newer cards that require more power often have a fan as well. Some cards require a direct connection to the computer's fan power leads because they draw so much power. Always check that your computer's power supply is rated ABOVE the amount needed for the card. The minimum number of watts needed will be printed either on the card itself, or in the user's manual.
On-screen images are comprised of millions of tiny dots, called pixels. The video card decides whether or not those pixels are turned on or off, resulting in an image with color, tone, and contrast.
Modes (See "Monitors Guide" for more information)
There are various display standards, or display modes. They specify resolution (width and height of pixels), color depth (measured in bits, and determines the maximum number of on-screen colors), and refresh rate (expressed in hertz-the number of times per second that the screen is redrawn per second).
Aspect Ratio & Wide-Screen
This figure is arrived at by taking the total displayed width by the height, and is usually expressed as a ratio, or fraction (x.y) Traditional TV and monitor screens have an aspect ratio of 4:3, or 1.33:1.
High Definition Television sets (HDTV) use an aspect ratio of 16:9, or 1.78:1, because such screens are longer, in proportion to their overall height.
The "big screen" theaters use an aspect ratio of 2.39:1, or 1.85:1, or 1.37:1. Recall that when you go to the movies, the screen is much longer, compared to its height, than a standard TV screen.
Most newer video cards support multiple aspect ratios. If they do not, then they cannot support Wide-Screen formats.
Display Device Support
Older cards may only have one output. This can easily be used with flatscreen monitors, with a low-cost adapter. Using more advanced display hardware, such as HDTV, requires a special connector, and a simple adapter will not work. Be sure to note the video outputs that a card has, so that you buy a card that is compatible with your video display(s).
Inputs
Some video cards have S-Video connectors or standard composite connectors video inputs that allow video capture from a TV or other video source, such as a camcorder or VCR.
Multiple Displays
Some video cards support more than one display output. That means the video card can send different signals to each display device. (Cards with multiple outputs may also be used to send the same image to multiple video outputs at the same time.)
Whether your card features one or more outputs, most computers will accept multiple video cards. Therefore, you can have a computer system with multiple independent video outputs, each displaying different images all at the same time.
Which is Best Suited for My Needs?
That depends on your application.
Dedicated Gaming
This is the market segment driving the sales of video cards; every family has at least one gamer who spends a sizable amount of time playing the newest hits, nonstop! For a card meeting such a hardcore gamer's needs, you will have to invest in a newer V card.
New games are optimized to run on the newest technology, enabling dazzling true-color backgrounds, smooth animation, realistic shadows and other special effects. If you're planning to buy that special gamer in your life a cool birthday present, be sure to select a card that's made for gaming.
Graphic Design/CAD
This is another area of use that requires a high-end card. Amination software, as well as Computer Aided Design (CAD) programs with 3D panoramic views, require a video card with ample power.
Family Computer
The family computer probably sees the most diverse activity: Browsing the web, running streaming video, playing games, and more. Multi-media home computers require a video card that can do all this. The "All-in-Wonder" ATI card combines the best of all multimedia features, at an entry-level price.
A brand-new top-of-the-line advanced 3-D graphics card may be overkill, especially if you don't have a gamer in the family, playing the newest-latest titles.
Office
Your office computer doesn't run programs using high-end graphics or 3-D animation, right? In fact, your office machines may be fine running in monochrome mode. Word processing, spreadsheets, and other programs do not require anything special.
Therefore, an older model or newer low-end graphics card would suffice. A computer used to browse the web may need something a bit more powerful. If you are planning to use the machine to work on multimedia presentations, you'll need something better still.
Just don't go overboard; match the application with the card. Outfitting every one of your office's computers with the fastest video card on the market would be an unwise allocation of resources.
Color Depth
Color Depth refers to the number of bits-per-pixel (bpp). A higher color depth lends a wider range of varying tones and hues. One-bit color is monochrome, as individual bits on the screen can only be on or off.
Super VGA, popular during the 1990s, featured 8-bit color. Truecolor is 24-bit, with eight bits each representing red, green, and blue. The total number of possible colors using TrueColor is 16.7 million. Some video cards can display modes that surpass the TrueColor standard.
Graphics Processing Unit
The Graphics Precessing Unit, or GPU (and less frequently called the Visual Precessing Unit or "VPU") is the "brain" of your video card. The GPU controls how your video card works, and renders 3-D graphics, as well as static screen images. The GPU chip also handles streaming digital video. This is the core of your video card. The GPU uses a multitude of transistors to perform lighting-fast calculations.
Clock Speed & Memory
The cards clock speed, or "core speed", is measured in MHZ (and Ghz) and notes how fast the card's GPU chip processes digital instructions. A faster GPU results in better performance, generally.
The RAM, or memory, is a number that represents the total free amount of space available on the card for the GPU to use as the frame buffer for the image on the screen, as well as a work space for the calculations that the GPU needs to perform.
The memory used today is often called DDR2 or DDR3. Generally, the more video RAM on the card, the better. The RAM speed is measured in MHZ (and Ghz). Having a good amount of RAM is good, but having memory that runs faster is even better.
Bus Width
The bus is the connection between the video card and the CPU. Some cards support 256-bit data transfer. That is like having 256 individual channels to transceive data between the GPU and CPU. Other cards have only a bus only 128 bits wide. A wider bus allows speedier communications between the CPU and GPU.
Pixel Pipes
A video card often has a fixed number of pixel pipelines, or number of processing paths that can generate one pixel (per pipe) per clock cycle. Each pixel pipelines is handled in parallel, simultaneously sending output to the video display(s). More pixel pipelines means 3D images will be rendered faster.
TMUs
Texture Mapping Units, or TMUs refer to the number of textures that may be applied during a single clock cycle. The video card uses program data to derive a color value for a given pixel, so that real-time calculations can create realistic polygonal textures, first creating a wire frame image, and then rapidly filling the frame with correct texture and shading.
Direct X
This refers to APIs (Application Programming Interfaces) that are used for games, usually for Windows. These include DirectDraw, DirectPlay, DirectSetup, DirectMusic, DirectXmedia, DirectSound3D, Direct 3D, and DirectInput APIs. These modules help make it easier for the CPU to communicate with the video card.
Making Sense of An eBay Ad
"PowerColor ATI Radeon 9800 256MB AGP 8X 128BitDirectX 9"
This was an actual video card sold on eBay recently. Let's see what all the numbers mean. Powercolor is the brand name. ATI tells us that the card is based on ATI's design. Radeon 9800 tells us the series and model. 256 MB refers to the amount of video ram on the card. AGP 8X tells us that the maximum AGP speed is 8X. 128Bit means that the bus is 128 bits wide. Direct-X 9 tells us that's the latest version that the card will support.
Pay careful attention to the details of eBay ads. The title will provide you with some general information, but for the specific details, check the listing carefully. If you are unsure about something, don't hesitate to contact the seller while the auction is still running. And remember to consider insuring the item, if the seller offers it.
Brands
Some generic brands will work just as well as the more well-known names, however you may want the reliability of a known performer. Some respected brand names include Powercolor, ATI Technologies, NVIDIA, Chaintech, Leadtek, MSI, Rosewill, XFX/Pine technology, and ASUS.
Different cards have different cooling systems, memory speeds, manufacturers, and graphics processor speed and type. When comparing cards, take careful notice of the technical specifications. Be sure that the card you buy meets or exceeds your present needs.
ATI or Nvidia?
ATI, or Array Technologies Incorporated (TSX: ATY, NASD: ATYT) is a North American graphics card developer and manufacturer. Further, some third parties have arranged to manufacture ATI's proprietary design, but often using their own modifications or enhancements.
NvidIA Corporation (NASD: NVDA) is ATI's major competitor in the high-end graphics and gaming card lines. NVIDIA makes its own series of cards, known as the GeForce.
There is an ongoing debate among gamers regarding which brand is best, however, there is no clear answer. It seems to be a personal preference.
Pricing
Video cards range in price. You can expect to pay from a few dollars to hundreds of dollars, depending on the specifics of the card. To get an approximate idea of how high auctions usually run for a card that you are interested in bidding on, check out the completed listings on eBay. Then, you can see what the card sells for, on average, and you'll have a rough estimate of how much you will have to spend to have a reasonable chance at a successful bid.
How Long Will My Video Card Stay Current?
You can use your card for years, however the newest graphics-intensive games demand the fastest cards. Therefore, if your goal is to play the latest games with the absolute best graphics possible, then you need to upgrade every year or so.
You can easily keep a card for a few years, because new games will often work on older cards, though the graphics will not display as well as a newer, faster card would. For some non-graphics applications, an older card is sufficient, and usually remains so for quite a while.
Used Cards
You can buy used cards on eBay. Some are used, others refurbished. Sometimes these cards have warranties. New cards are also widely sold on eBay.
Drivers
Most video cards require the use of special files, called drivers, as well as additional software. When buying a video card new, there will likely be a CD with software bundled with the video card. Buying a card used on eBay, and you may, or may not, also receive the drivers.
If the drivers and/or additional software is not included, you can usually go to the website of the company that makes the card and download the drivers for free. Note that drivers and other video card software are often updated to correct problems, add features, and improve performance. Check online for updates, and download and install as needed.
Be sure that the software that you are downloading will work with your operating system! If you are running Windows 98, for instance, you are limited in that many newer video cards do not offer software or drivers that will run under your operating system. Check before buying, as a card without the proper drivers or other software will not work at all!
Overclocking/Flashing
Overclocking refers to resetting the default parameters of the video card. The clock speed of the Graphics Processor and memory on the video card may be sped up. This requires more voltage to the card, and more voltage creates more heat.
Without a good knowledge base, overclocking is not recommended. Good ventilation is a must! If a card runs too hot for too long, it will not work properly any longer. This also reduces the total number of useful hours the card will perform before eventually failing.
Flashing refers to replacing the card's firmware with a newer version. Some cards can be upgraded to run like other more feature-rich cards, higher in the series. This is another dangerous procedure, and must be done with extreme care. It is not recommended unless you know exactly what you're doing. A card that has been improperly flashed, or flashed with the wrong firmware will not work.
Benchmark Testing
Benchmark programs assess a video card's performance, after checking the card's capabilities. Many benchmark programs will calculate a score, or list a set of parameters detailing the card's performance. Some such programs include 3DMark, 3DBench, WinMarks, WITS, and WinStones.
Common metrics used are "polygons-per-second" and the "fill rate". A higher fill rate allows higher resolutions and more colors at a higher refresh rate.
© Copyright H. Miller 2oo6 - 2007, All Rights Reserved
Guide created: 05/04/06 (updated 06/30/09)
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