I'm currently building a new PC and am planning to go SLI. I already have one Gigabyte GeForce GTX 570 1280MB Overclocked; the problem is that the place that I buy from no longer has this card. They DO however have the Gigabyte GeForce GTX 570 1280MB Overclocked V2. Will I run into any issues using these two cards in SLI, or do they have to be the *exact* same card?