AGP 1x with local texturing (direct memory access or DMA)
This is the least expensive and lowest level of AGP.
AGP 1x cards copy all textures from system memory into their local frame buffer prior to moving them to the video processor.
Although this is the same process used by today's PCI cards, the AGP 1x has a faster bus - 66MHz vs. 33MHz. (1x means the card sends one data transfer per cycle)

AGP 1x with direct memory execute (DIME)
This level of AGP runs faster than 1x with DMA.
Direct memory execute mode (DIME) goes directly to the system memory for textures and pulls them directly into the graphics processor.
It may also use local memory for texture memory management.
This level AGP card may or may not use sidebanding.

AGP 2x
This level of AGP is characterized by the use of direct memory execute mode and sidebands.
A sideband is an additional data path to the system memory apart from the main bus.
It takes the address and command instructions from the main bus and sends them on a sideband to the system chipset.
Sidebanding lets the graphics processor line up new data requests as the main bus continues to gather data.
This increases the AGP bandwidth and speeds up data transfers.

AGP 4x

This level of AGP has not been released.
The AGP 4x level will move 4 32-bit data transfers per cycle.
The 4x level will require cards to use sidebanding.
This technology is still under construction, as the system memory bus speed and core-logic chipset will need to handle commands and data moving at 266MHz, four times the speed of the AGP 1x.

A sideband is an additional data path to the system memory apart from the main bus.
It takes the address and command instructions from the main bus and sends them on a sideband to the system chipset.
Sidebanding lets the graphics processor line up new data requests as the main bus continues to gather data.
This increases the AGP bandwidth and speeds up data transfers.

Local texturing (direct memory access DMA)

In local texturing mode, the graphics card copies entire textures from the system memory into the onboard frame buffer memory Then it moves it to the graphics processor.

Direct memory execute (DIME)
In direct memory execute mode, the card goes directly to the system memory for textures to pull them into the graphics processor.
This allows the card to use as much memory as it needs instantly instead of relying on onboard memory.
This is also a dynamic allocation;
when the memory is no longer required by the software, it returns it to the system for other uses.
AGP cards that use direct memory execute may or may not be able to use local memory also.

Local texturing and direct memory execute (DMA/DIME)
AGP cards that support both local texturing and direct memory execute use the system memory for textures to pull them into the graphics processor.
This allows the card to use as much memory as it needs instantly instead of relying on onboard memory.
Then it uses the local memory (on the card ) for the frame and Z-buffering.

The amount of memory that exists on the board.
A display adapter's memory is set aside to store the image that you see on the monitor.
If you have more memory, you have more resolution size and color range choices.
There is no strict formula for figuring out the amount of memory you will need, but a good measure is a 4MB card for basic business applications and an 8MB for general performance.
For 3D gamers, CAD/CAM professionals and graphic designers, it may take 16MB to provide the performance desired.

This field indicates which graphics chipset is used by the video card.
A card's chipset, more than any other component, determines its capabilities, its features and its limits.
Before choosing a video card, research which chipset offers the features and the processing speed that best meet your needs.

This field indicates whether the graphics card has a TV-out port, which allows you to connect a television set to the card for use as the main display.
The advantage of using a TV as the display is that the television often has a larger viewing space than your computer monitor, which is especially good for viewing movies played from your computer's DVD-ROM drive.
The disadvantage of using the TV as the main display is that most televisions are limited to lower resolutions (640 X 480) than computer monitors.
The TV-out port appears on the back of the card next to the ordinary VGA port, but normally you should not have a television and a monitor connected at the same time.
A graphics card with TV-out support will not usually be capable of displaying to both the television and a computer monitor simultaneously, unless the card's manufacturer states otherwise.

This field indicates the highest resolution at which the video card can display 24-bit True Color, which has a color depth of 16 million colors.

Rule of thumb: The higher the resolution, the sharper the image.
Unless your presentations contain high-end graphics, such as motion pictures or precision CAD/CAM drawings, resolution should not be a large part of your purchasing decision.

There are three standard video support formats in the world.
NTSC is the North American and Japanese standard.
PAL is the European standard.
SECAM is the standard for France only.
Think about where you're showing your presentations when considering the appropriate support formats.
For example, choose an NTSC/PAL supported projector if you're showing your stuff in the U.S. and Europe.
But if France is on that itinerary, be sure the projector has SECAM support, too.

The JPEG file format compresses graphics of photographic color depth better than competing file formats like GIF, and it retains a high degree of color fidelity.
This makes JPEG files smaller and therefore quicker to download.

MPEG is a standard for compressing sound and movie files for downloading across the Internet if desired.

This field indicates whether the I/O card complies with the Plug and Play standard, which makes card installation much simpler by allowing the Windows 95 or 98 operating system to setup and configure the card.