Help. I'm tearing my hair out here. I've just installed two new MSI 780ti gaming cards into my system and SLI will not work. My mainboard is a MSI Z68 B3 with an intel i7 2600K cpu running at stock. My psu is an OCZ ZX 1,000watt. At the moment all I have plugged in is an SSD and usb for my keyboard and mouse. Fresh install of windows 7sp1. No matter what driver is installed they all do the same. The game will attempt to launch in SLI mode, flicker and either hang on a blank screen, or CTDT with the nvidia message saying the driver has recovered. Before I had a pair of GTX680's working fine, I've even tried a couple of AMD's R9 290X cards in there and they work fine. I don't get it! In the review for these cards they recommend a 800Watt psu so I should be covered and the fact the AMD cards work prove that. I have also ran both cards by themselves and they test fine, similar temps and fps, so it's not a duff card. Tried a different bridge, it's not that. Moved the cards in different slots. GPZ's little test works but nothing else does. Any suggestions welcome.