Wow, this is very impressive my friend ... remember reading about your hardware on here before.
I recently bought an Asus Rampage IV Extreme board socket 2011 build too, but went the whole hog for the I7-E 3960X as a pre overclocked 16 GB bundle at a guaranteed 4.6 GHz and in the past month or so of owning it, its not missed a beat.
http://3xs.scan.co.uk/ShowSystem.asp?SystemID=1374
I also have a GTX 680 2GB in use in this machine, with SSD's too for mainly flight sim ... in hindsight I should have waited for a GTX 780 or just the GTX 680 with a currently available 4GB for the higher resolutions I need.
It looks like you have went for the ultimate in many ways, but why not a 3960X? I know it only offers about 100MHz over a 3930, but the 3930 lose's out in cache too and not by much I admit, but there are other difference that probably only Intel could tell us ... but on CPU cache is important for what I do.
4 x 580's Wow, still we have 680's now.
I'm not knocking you mate, even you have to build within a budget I guess.
Highly
highly impressive ... WTG
BTW here is link to my recent socket 2011 stuff
Its in that thread somewhere pics too.
http://forum.1cpublishing.eu/showthread.php?t=31872
Let me know what you think, more than does the job though for all Flight Sims I own