I have a 6-core (12 thread) Xeon at work. (E5-2620), and a 3-core (8-thread) i7-Extreme at home. (i7-3820K). It’s kind of hard to test performance because my GPU in work is a bloody Quadro K4000 (don’t ask), whereas at home I have a GTX 980. GPU performance is (as expected) utterly mental at home, but sucks in work. I also use Quad-Channel 1600Mhz Memory at home.
My Work PC certainly throws data around faster than my home PC, it can certainly load textures into memory much quicker, but for actual processing I’d say my i7 is faster. I could do a CPU test in-engine I suppose.
My Work PC tends to throw data around much quicker than my home PC, but my home PC actually processes it faster. In real terms, I honestly don’t think the Xeon out performs the i7 at all. In fact my home PC is actually faster for rendering applications too, like Maya and Max, but that could be a number of factors contributing to that. Given a choice, I’d take the i7, unless you’re going to overclock the Xeon to similar speeds. (Good luck getting 6 cores stable at 3.3-4.0 Ghz though :p).
Honestly, just save money where you can on CPU and go for a monster GPU instead. GTX 980’s are notoriously cheap compared to their predecessors 