I currently own a ASUS Maximus V EXTREME LGA 1155 Intel Z77 motherboard & have a EVGA GeForce GTX 680 2GB 256-bit GDDR5 PCI Express 3.0 x16 video card, i would like to add another GeForce GTX 680 to the board but i'm not sure what PCI Express slot to use. Obviously the video card i have now is in the first PCIE_X16/X8_1 slot, there is also a second PCIE_X16_2A slot right below it & third PCIE_X8_2B right under that, there are two other slots titles PCIE_X8_3 & PCIE_X8_4 making five slots in total. SO if anybody has any experience running a SLI setup? i would appreciate some input. Thanks in advance