I honestly don't know, but if you already possess 4 780 Ti's, I'd recommend selling all four and buying two 980 Ti's in placing in SLI. Or buy just one 980 Ti, and put the extra money into a safe place, for when Pascal releases. You could also buy one 980 Ti with the money and use the remaining cash to upgrade the rest of your system. On Ebay, a used 780 Ti is could fetch you at least $300.
I honestly don't know, but if you already possess 4 780 Ti's, I'd recommend selling all four and buying two 980 Ti's in placing in SLI. Or buy just one 980 Ti, and put the extra money into a safe place, for when Pascal releases. You could also buy one 980 Ti with the money and use the remaining cash to upgrade the rest of your system. On Ebay, a used 780 Ti is could fetch you at least $300.