Take it from me... or my 2 cents,
I did the math going to X79, I was ready to by a RIVE black 4930k, 16GB of ram...
Then a light bulb went off... "What is the real % increase: Swolern and I on OCN did some benches..."
He had a 3930k and tri titans, I had a i7-930 @ 4.4ghz(now I use a X5660 @ 4.56/4.7and selling the 930).
X79 at most with 1vs2vs3vs4 way titans in SLI Surround, no doubt was faster but for 10 more FPS is this worth it for you? To me 100% no. I am also in the high end, I run 4 monitors game at 4800 x 2560 (thats higher than 4k), and use the 4th as an accessory. Why go and spend $1k-1,500 for a mediocre performance gain. PCIE 3.0... no, it is minimal.... More clock??? Have you seen Kara's marks with the Xeon.
To me the better upgrade is used elsewhere:
Samsung Pro 840 SSD check
Titans check
Monitors check
add more ram check
nice mouse check
nice OMNI soundcard check
Headphones to go with it check.
You are welcome to disagree but X58 is a live and well, is it worth paying retail? I leave that up to you but my 930 is not as good as my xeon but its pretty far up there, then with my gigabyte x58-ud5 rev 2.0 It kinda speaks for itself. I am not here asking for bones BTW. I just want you guys to think long and hard before you spend money on an "upgrade" which at the end, I believe it is, but for me I run thief at close to 60FPS the only time I wish for an "upgrade" is when I game with something like Metro Last Light or Titanfall, but thats not due to my system thats due to the game not being properly setup for SLI.
Setup is here:
http://imgur.com/a/j4rt4