Hi, I'm looking to add a video card for SLI and I can't find another of the exact same P/N number (02G-P4-3662-BR). The card I have is a GeForce GTX 660 Ti Superclocked. I do see other GTX 660 Ti cards but the P/N numbers don't match. Is this anything to concern myself with? My rig is a i7-3820, Gigabyte X79 UP4 mobo, 16 GB RAM, Windows 8.1 Pro. Thanks!