First question, is that power supply enough? It's not on nVidia's list, but no Rosewill's are. It's got enough channels and volts as near as I can tell, but I'm not 100% on that
Second question: is dual 16x required for your cards to perform at maximum capacity?? I've seen several posts/writeups that say 16x gets you very little benefit from dual 8x. Well, I ran 3dMark and scored 19500ish vs 23000ish that's on the 3dmark chart here on TomsHardware.
So basically, I'm wondering why I'm a good 4000 lower, and what I can do about it while I still have time to return things to newegg :-)