NVIDIA Scalable Link Interface (SLI) is a technology that allows one computer to utilize multiple video cards simultaneously. By harnessing the power of the extra video card, a computer can achieve superior performance in games than it couldn't with only one card. In 2007, NVIDIA introduced an upgrade for SLI called three-way SLI that allowed up to three video cards. Three-way SLI can improve a computer's gaming performance, but it has several requirements.
Background
In an SLI configuration, at least two NVIDIA video cards are installed in the same motherboard. The monitor is connected to the "master" video card, which displays the combined output of all video cards in the SLI configuration. The video cards split the workload needed to render a three-dimensional scene by each rendering a portion of the scene before combining it into a complete picture. Because the communication between video cards could overwhelm the data transfer bandwidth of the motherboard, video cards in an SLI configuration communicate directly with one another over a specialized connector called a bridge. Three-way SLI increases gaming performance further by adding a third video card to the configuration.
Operating System Requirement
NVIDIA three-way SLI requires a computer running Windows Vista or later. For best performance on a Windows Vista-based computer, download Microsoft update 945149, which distributes the graphics workload more evenly on a computer with multiple video cards.
Compatible Hardware
Three-way SLI requires three compatible video cards and a motherboard with a compatible NVIDIA nForce chipset. The NVIDIA nForce 680i and 780i chipsets support three-way SLI. The compatible video cards as of March, 2011 include the NVIDIA GeForce GTX 260, 280 and 285, the GeForce 9800 GTX and the GeForce 8800 GTX and Ultra.
Power Supply Requirement
Three high-power video cards create an incredible load on the computer's power supply. Additionally, each video card requires two auxiliary PCI Express power connections. When building a computer for a three-way SLI configuration, select a power supply with a maximum rated output of at least 1100 watts and six auxiliary PCI Express power connectors. The power supply may have six 6-pin PCI Express connectors or four 6-pin connectors and two 8-pin connectors.
Tags: video cards, video card, auxiliary Express, auxiliary Express power, cards configuration, compatible video, compatible video cards