I am about to pull my hair out.
I have a stable 850watt PSU that I've been using for a few years now. I just got this new mobo, Asus Maximus Hero VII, and 2nd matching video card today and have spent the last 7 hours troubleshooting.
I can get both cards to run individually just fine. I can get both cards to run in either of the two slots my mobo has that work with SLI just fine.
If I enable SLI and try to play any of my numerous games it just goes to a black screen and I have to reboot.
If I disable SLI on my system and then set the games to run in Windowed mode, SLI works great (once I enable SLI again in Windowed Mode). I'm already running the 344.80 non released driver from nVidia and no joy.
I've seen several other people on the Googles complaining of the same thing trying to get 3 way SLI to work and a couple with my exact same issue. I can't seem to find any solution that applies to me.
Any ideas?