Neptune:

I have the same problem and I am running 2 480 GTX's. I have reason to believe that the driver support for the 400 series is terrible. Nvidia seems to have pushed the 480's to the trash to focus on their newer cards now. The last WHQL driver for the 400 series was in January and is still the latest. When using the standard SLI profile with whatever latest driver is out, my opening CG flickers so bad it hurts my eyes. I also cannot enable depth of field in game with the standard SLI profile. Anytime a spell is cast or a teleport is used (while DoF is enabled) the game becomes very choppy and unplayable. However, when I disable DoF my game runs fine. I love DoF and I have a nice system so there shouldnt be any reason to disable this feature. For now, I am using a custom profile to fix this issue with SLI Tool. I use the Crysis 2 SLI profile and paste that over the XIV profile. This fixes 2 things but adds another It fixes the flickering CG at the start and it allows me to use DoF with no hiccups. In place of this, my in game cutscenes now flicker really bad when the scene fades out of one and into another. Its annoying but I don't see enough cutscenes anymore for it to be a problem right now. Hope this helps.