So what is SLI? Well to simply put the acronym SLI stands for “Scalable Link Interface” it is this technology which closely resembles the ’90s 3D Voodoo based boards which could be connected to your regular 2D video card via a 15-pin D-SUB vga cable and enable you to play 3D games with the help of the voodoo 3D chip. In some cases you could even couple 2 voodoo cards via this cable and enjoy fast frame rates. Forward a decade and a more innovative solution is introduced by 3D graphics king nVidia named as SLI (Scalable Link Interface) these requirements for an SLI to function properly is an SLI-enabled motherboard which is based on an nForce4 chipset, and SLI-enabled graphics boards by nVidia or more specifically the 6000+ series video cards by nVidia.
The SLI setup has seen emerging usage and huge acceptance by the enthusiasts community. Watching nVidia make huge numbers on the sale of the SLI setup, ATI and Intel jumped on in with their own technologies.
ATI introduced their cross-fire technology which does a similar thing and couples two RADEON based video cards and a motherboard that would support such technology.
Again these setups are hugely focused for the enthusiast community that is sitting on the cutting edge of the latest technology.