Motherboards That Support Dual Graphics Cards
By Steve Lander
Using multiple graphics cards can give you more processing power and better graphics performance, but you need a special motherboard to do it. The two primary graphics processor manufacturers as of 2013 -- ATI and Nvidia -- both have technologies that enable you to use two, or at times more, graphics cards at once. If you frequently engage in graphically intensive tasks like video editing or 3-D modeling, dual cards are a means to getting enough computer power.
Dual Card Certification
Depending on whether you want to use ATI or Nvidia graphics cards, you'll need a motherboard that's either CrossFire or SLI certified. These motherboards have the slots and hardware channels to enable you to plug at least two graphics cards in at once. They also have been tested by the manufacturers to work with a multi-card connection. Nvidia even tests some boards to support three cards instead of just two.
A motherboard's physical configuration has an impact on whether or not it will support dual cards. It needs to have at least two PCI-Express slots. Furthermore, the slots must be positioned in such a way as to physically accommodate two cards, especially given that graphics cards can be relatively large. Some motherboards designed for dual-graphics card applications move the RAM, for instance, so that the memory sticking out of the motherboard won't get in the way of the graphics cards.
Other Computer Requirements
Running dual video cards requires a case that can accommodate them. Having two video cards also means having two powerful processors that potentially consume hundreds of watts of power. As such, your computer will need an upgraded power supply with multiple power connections. Dual-card computers also need cooling systems that can handle the additional heat that the graphics cards generate.
Single vs. Dual
Dependeing on your application, a dual-card configuration may not be the best option. Even in the best scenarios, two cards won't be twice as fast as one card since both CrossFire and SLI technologies have some overhead. In addition, if your software doesn't support multiple graphics cards, you won't get any performance benefit out of a setup and would be better served to spend the money to get one faster graphics processor.
Steve Lander has been a writer since 1996, with experience in the fields of financial services, real estate and technology. His work has appeared in trade publications such as the "Minnesota Real Estate Journal" and "Minnesota Multi-Housing Association Advocate." Lander holds a Bachelor of Arts in political science from Columbia University.