Which processor were you looking at because the cheapest 8-core Xeon that I see from a quick scan on Newegg is $900 and that thing only runs at 2.0GHz? If you want better performance than a current-gen
stock 6-core IVB-E processor, then you're looking at about $2,000 for one that runs at 3.1/3.4GHz (E5-2687W). And remember, current generation Xeons
don't support overclocking, so the frequency you pay for is the frequency you are going to get.
When a game is CPU dependent then that means it also thrives off of the frequency of a core, and in the case of the desktop i7 chips, they're unlocked so you can potentially get another 500MHz - 1,000MHz out of the chip (or more if you have sufficient cooling) for free.
The only time I would ever suggest gaming with a Xeon is if you had been given one for free (or paid very little for it) or if you did other things with your computer that warranted the need for those cores in addition to just gaming.
Here's a review that pits the 3970X against one of the $2,000 8-core Xeons I mentioned from Newegg, but it also shows a stock 3930K in the list of benchmarks as well -
http://www.tomshardware.com/reviews/cor ... ,3348.htmlThe gaming section for the review above is actually pretty terrible since it looks like they're heavily GPU limited, so I would honestly focus more on the non-synthetic workload section instead where the GPU is not a factor.