ASDFJAVOIRM :
YOU Take SLI CONNECTOR OFF!!!!!!!!! Then you no get ERROR FOR CARDS! DUUUHHH
As was pointed out, he does not have the connector attached. Duh!
So...I do not know. I've never had this issue, but then I've never used two different Nvidia cards together (I have with Nvidia and AMD).
What version of Windows do you have?