So in computers, many boards support multiple gpu's. Many boards have many pci slots for stuff like gpu's. When you use 2 gpu's, must be of the same type like your using, you must use sli (Nvida) or crossfire(Amd). In your case, its sli. So you must also have an sli bridge. What is your motherboard model? Make sure it supports sli as the way your talking, idk if you know this. Keep in mind though, if you run sli, some games do not support sli and you might either get the same results as 1 gpu or it might actually be worse than 1 gpu. However, if the game does support sli, then your fine as you will see an improvement by using 2 gpu's of the same type with the sli bridge and making sure motherboard supports sli and psu can handle another...