The OP mention a i7 3820. I would choose that over ivy bridge in a heart beat. You can OC them to 5ghz fairly easily and if you get a decent enough x79 mobo, you will be able to upgrade to ivy bridge extreme CPUs in the future. Right now both the AMD 990fx and the intel 1155 are both dead platforms. X79 is still somewhat future proof. Plus You don't have the heat problems, you can fit more memory on the mobo, you have better capability for SLI or crossfire if you want it, if in the future you start doing a lot of video editing, you will have the option to upgrade to a 6 core CPU where as socket 1155 will be stuck with a 4 core CPU.
In all reality x79 is the smartest thing to do. The ONLY reason I went with ivy bridge was to see if I could break the 4.8ghz wall that the ivy bridge chips seem to have. Otherwise I would have gone with x79 all the way.
