Purchasing a video card for your desktop should be considered as one of the first performance upgrades you can make to your existing computer. If you bought your computer as a complete unit from a retail outlet, or an online computer store, chances are that your computer only has an on-board graphics processor.
What does this mean to you? An on-board graphics processor is typically a very small chip that shares its memory with your existing system memory. It is mounted on the motherboard and is usually several generations behind the latest graphics cards. Even if you don't play games, or design graphics, you will experience a significant increase in speed by adding, or upgrading to, a recent model graphics card.
First, you will be off-loading all graphics processing to what amounts to a separate computer system within your system. The graphics card processes all commands to generate graphics on your system, leaving your processor free to tackle other tasks. The graphics card has its own memory, which is faster than your system memory, and thus your computer will also have more memory available to it to use for other tasks.
While there are dozens of graphics card manufacturers, there are really only two major companies that produce the chipsets found on these graphics cards: ATI and NVIDIA. These chips are known as GPU's (Graphics Processing Units) and are the real brains behind each card. You'll see their popular brands, like Radeon, All-in-Wonder, and Crossfire for ATI products, and nForce, GeForce, and Quadro for nVidia products.
When you purchase a graphics card, you first need to determine what type of graphics interface you have on your motherboard. The three types are PCI, AGP, and PCI-E. Almost every motherboard has an available PCI slot. But the PCI interface isn't particularly fast compared to the other options, so check to see if you can use an AGP or PCI-E. If not, consider upgrading your motherboard first to take advantage of the faster speeds. An AGP slot is usually colored (often green). You'll want to find out from your motherboard manufacturer if your AGP slot can handle the fastest AGP cards (8X) instead of the slower older cards (4X and 2X). If you have a fairly new system, you may be lucky enough to have a PCI-E (PCI-Express) slot. This will allow you to use the fastest graphics cards on the market today. Be aware, though, that these graphic cards can be more expensive.
The second thing that adds to the price of a graphics card is the amount of memory that the card has. A typical on-board graphics processor has 32Mb, but graphics cards start at 64Mb and have as much as 512Mb. The more memory, the more likely your computer will handle graphics with ease and not temporarily freeze. It also allows fast switching between applications, or tabs, and it is especially helpful with games that can have hundreds of frames stored in memory at any given moment. 3-Dimensional games, such as first-person shooters and flight simulators are especially memory intensive.
The last factor is what other features you might need. Graphics cards offer Super-Video output, TV-tuner inputs (for recording video for multimedia projects), and much more. Be sure that your graphics card can do everything you might need it to do for the future.
So, before you upgrade your hard drive, add more memory, or buy a second monitor, strongly consider the purchase of a dedicated graphics card from ATI or nVidea to give your desktop computer a real power boost.