Originally Posted by
Taotaisei
Xeon processors are built for workstation and server environments. They are often binned to increase their reliability and lower things such as heat. They are not designed for the HEDT environment that you are likely building your computer for. On top of that, the Xeon's tend to have more instruction sets, a larger registry, allow for multiple physical processors on a single board, and ECC memory compatibility. Which, again, likely isn't useful for you, but is nigh on irreplaceable for many data centers.
If $500 doesn't sound like all that much for a processor, you likely want to be looking at the i5-4690k or the i7-4790K as the processor you'd like. The first of which is regularly suggested in computers coming in at an over $800 budget. Most video games don't support over 4 cores and many, such as WoW, put greater stress on a 1 or 2 cores for the majority of the work load. There are games such as Battlefield 4 that are capable of using all cores+hyperthreading but understand that it's a rare case for this rather than just 2 or 3 being used. In multithreaded situations the 12 core 24 thread xeon is going to kick ass, but as soon as it's put into a gaming environment the 4690k is likely going to beat it once overclocked.