PCI Express 16x is the fastest technology.
Choose PCI Express over AGP for speed if you have the option.
Choose AGP or PCI Express over Standard PCI if you have the option.
Standard PCI is the slowest option. It will work, but you will not have the best performance.
USB, USB Wireless and other wireless video cards will not work.
See picture below to determine which slot(s) you have available on your motherboard keeping in mind that your existing video card is normally removed so that slot may be available, too, and you may have more than one of each. To do this you will have to pop the cover off of your PC to get a look at your motherboard.
We recommend using a Single PCI Express or AGP video card with two video outputs over using two video cards with single outputs. This makes setup much easier.
The slots that you have available will determine which video card(s) you can use.
Video Card Size
Make sure the video card you purchase will fit in your computer case. Slim form factor computers will require a low profile video card. Some gaming graphics cards are very large and may not fit in some smaller computers.
Video Card Power Requirements
Some high end video cards have specific minmimal power supply requirements. Check the hardware requirements for the video card you purchase to make sure your computer has the appropriate power supply to handle the new video card. If not, you may have to upgrade the power supply unit in your computer.