Understanding Display Adapter

THE TWO MAJOR TYPES OF DISPLAY ADAPTERS
 

Currently, display adapters come in two common varieties: PCI and AGP

PCI

The major standard in display adapters before AGP came along. More than adequate for everyday computing, internet surfing, etc, it's inability to process data for 3D gaming and other highly graphics intensive applications make it inappropriate for some of today's games, and design programs. The card's data bus maxes out when 3D graphics have to be rendered.

PCI Display Adapter

- A PCI video card. - Notice that its data bus is a typical PCI setup, with a single ridge to orient the card. - This particular card has a fan over it GPU (graphics processing unit). - The four chips over the GPU and to its right are the video RAM. - The large chip to the left of the GPU is the video BIOS. - Good for everyday computing (ie Word processing, internet, etc).

AGP

Accelerated Graphics Port: The current standard in display adapters. The AGP card uses a special slot on the motherboard and utilizes the main system RAM to render 3D graphics. Thus, theoretically, AGP cards can use an unlimited amount of RAM. The AGP chipset allows the data bus to directly communicate with the main system memory. This is called Direct Memory Execute (DIME). AGP uses main system memory to render graphics processing, without using the main system CPU. This frees the CPU to perform its other tasks.

AGP performance is measured in how many times it sends data per single clock cycle. The newest AGP cards are rated at 8X (ie, data is sent eight times per single clock cycle). The higher the rating, the higher the graphics throughput.

 AGP Display Adapter

- An AGP video card - The AGP data bus consists of up to 3 ridges and more connectors than a PCI card, allowing more data to flow. - AGP processes most video data in its GPU. It ises main system RAM to render 3D. - This GPU also has a fan. - Notice the video ram on top of and to the right of the GPU.

 

The AGP card is inserted into the AGP slot on the motherboard.
The AGP slot on the motherboard

- The AGP slot is a proprietary slot that only an AGP card will fit into. - An AGP video card uses direct memory access for video. - The CPU is not used, freeing it up for other functions.