check out the 3 games they list there, performance is almost the same, email@example.com = 975extreme.
You should have researched more before ordering a 990X, but i dont think thats a problem for you, you seem to have a lot of cash lying around you to just order upa $1.000 bucks cpu before doing a proper research.
The 990x its only better than bloomdfield at multi-threaded apps.
the 2600K is far better than the 990X at games, and overclocks MUCH more....
About 4.3 for gulftown and 4.8 sometimes 5ghz with sandybridge.
If i were you i would cancel your order and order up Sandy Bridge, or wait until X79.
The performance boost you get from bloomfield to sandybridge aint that much.