eVGA GeForce 7950 GX2: One Card, Double the Fun
 

It's hard to believe that almost two years have passed since Nvidia first introduced SLI—or should we say, re-introduced it. The idea that you can use two consumer graphics cards in parallel to nearly double graphics performance goes back to the days of 3dfx, where two PCI graphics cards would draw alternate lines in "scan line interleave" mode. The proliferation of AGP graphics pretty much killed that concept, but the flexibility of PCI Express brought it back. As PCIe graphics started to take hold, Nvidia introduced its own SLI—Scalable Link Interface—together with an nForce 4 motherboard chipset that sported two graphics card slots.