I get much better performance on a i7-4930K OC to 4.0 ghz with a GTX 680 and a raid 0 2x250 gig (samsung evo) SSD setup. Just 2 drives total in the machine in raid 0.

Than a i7-3930K overclocked to 4.2 with a GTX 690 (fastest bench marked card on the nvidia site, even faster than titan) and a single dedicate gaming SSD.

Both have 32 gigs memory.

I'm starting to think the Raid 0 SSD makes a decent difference with tons of wow's open.

Just a note - the i7-4930K uses a different socket, so you can't just pop it in your existing motherboard. It can also use up to 64 gigs memory.