Hey everybody. I've been searching around the forum all day and I've learned quite a bit so far. However, I'm currently demoing the Octane Render engine and it is powered by CUDA (as well as Adobe CC), and I'd like to get more processing power (multiple GPUs), without getting into adding PSUs. I understand that there are wattage issues per slot (250 watt), but I have run across a few posts here that seem to err on the side of adding PSU, with nearly every dual GPU setup. I'm pretty sure I can run dual GTX 660s without issue, but what I were to keep my 660 to drive my displays, and get an additional card to run in the background for my CUDA applications? For example, can I keep my 660, and put in a 680? 770? or 780? Conventional wisdom might deem the 780 a definite no, but I know Macvidcard can modify them to run w/o additional power. Would I be limited to just one card then? If not, I think it would great to add a 770 or 780 in the background. Thoughts?