About Video Memory Cards

Graphic Processing Unit

The Graphic Processing Unit (GPU) is the core of your video card. It processes graphic information the same way that your Central Processing Unit (CPU) processes data for your PC. Its speed is ultimately the speed of your video card, so the faster it is the faster your card will be able to manipulate photos and render 3D games.

While the GPU determines the processing speed of your video card, the memory determines how much information it can process at once. The more memory it has, the larger the files it can simultaneously manipulate. Ultimately, large memories also lead to a boost in speed. If you're looking for a fast card, ensure that it has both a strong GPU and a large amount of memory. Memory comes in the form of Random Access Memory (RAM). As of 2010, 256MB is considered low-end, while 1GB of RAM is high-end.

Motherboards are particular about what types of video cards they'll accept. There are two main interface formats: AGP and PCI-E. AGP is largely outdated and rarely appears in new motherboards. PCI-E has several versions, including PCI-E 1.0 x1, x2, x4, x8, and x16. It also has a PCI-E 2.0 x16 model. These are generally interchangeable, so you can install a PCI-E 2.0 card on a PCI-E 1.0 motherboard and most likely it will work. However, it will not work at full power. Instead, it will be restricted to the performance of the 1.0 interface. So in the example above, the PCI-E 2.0 card would operate at the lower levels of the PCI-E 1.0 card. AGP and PCI-E are not interchangeable.

The video card's output ports determine what kind of monitor it can support. Older monitors use VGA cables and need a VGA output while high definition models use DVI or HDMI ports. In addition, some video cards have input ports to allow you watch cable television on your computer.

DirectX is Microsoft's graphics software. It is a core part of many video games, and significantly affects the games' look and speed. Not all graphics cards support all forms of DirectX, however. DirectX 11, for instance, will only work on video cards manufactured after fall of 2009, and then it only works on some of them. Instead, earlier cards must utilize DirectX 10 or even 9. This may restrict you from enjoying certain games or taking advantage of particular graphics features.