According to my Mobo specs I have 2 pci-e 3.0 slots and 4 pci-e 2.0 slots. I want to add in a second video card GTX 660Ti, do I have to put them both on pci-e 3.0 or 2.0, or can I mix and match, I don't want to overheat my computer or cards so I won't overclock them but I want to make sure they stay cool. Right now the one that is in there is 111 F while playing games. I have a side fan on my HAF will it be okay to put in the extra card?
More aboutwant video card
Check your motherboard manual. Also, having 2 PCIe x16 slot doesn't necessarily means your motherboard supports either SLI or crossfire. What motherboard are you currently using?