For the gamer, there is no more important part of a computer than the video card. The video card's job is to take image information provided to it by the CPU and render it as an image on the computer's monitor. The higher-quality the video card, the better, more defined, and more complicated the image can be. Obviously, someone who is interested in 3D graphics or video editing is going to be shooting for a top-of-the-line graphics card, but what about the rest of us? Do we really need the latest $500 offering? It turns out, unless you're one of those gamers mentioned above, the answer is: probably not.
Getting Down to Basics
Video cards, in a lot of ways, can be thought of as miniature computers. They have processors on them, but instead of being called a "CPU", they're referred to as a "GPU", or graphics processing unit. They also have memory, measured in megabytes (MB's) or gigabytes (GB's). They are, essentially, small, very specialized computers that work in conjunction with your computer's CPU to deliver images to your computer's monitor.
So when we're weighing one video card against another, we look for a lot of the same criteria. How much memory does it have? How fast is the GPU? Of course, when talking strictly about numbers, the higher the better.
Descrete versus Shared: What's the Difference?
In the world of video cards, there are two general categories that all cards fall into: descrete and shared. The terms "descrete" and "shared" actually describe the memory scheme the video card uses. In a "descrete" video card, the video circuits have their own set of memory chips. This scheme is also commonly referred to as "dedicated". In a "shared" video system, the memory is actually shared with the CPU. This is significant is two ways. First, this means that whatever memory the video card is using at the time is not available for use by the CPU, therefore effectively lowering the total system memory. So a computer with 2 GB of system memory and a shared video card that's using 1 GB of memory for graphics really only has 1 GB of system memory available. This is usually not an issue, but can cause problems if you're running a high-end video game or editing video on your computer. Second, a lot of times system memory is actually slower than dedicated video memory can be, so "shared" video cards tend not to be able to handle the same amount of information that a descrete video card could.
So How Do I Choose?
As with all other parts of a computer, it really boils down to how you're planning on using the machine. If you're only going to be using it for non-visual media functions, such as reading and writing email, creating documents, spreadsheets, and databases, or surfing the web, then a shared video card will probably do you just fine. If you're more inclined toward visual media, such as video games, video editing, or image processing, you're probably going to want to get your hands on a descrete video card. How much memory and how much GPU processing power is up to your budget.