Your motherboard allows for overclocking and you should do so. You should be able to easily get that processor up to 3ghz and beyond which will make it fine to pair with an HD4850. At stock it will certainly limit the card in the more CPU intensive games.
It's really not a particularly hard thing to do. Essentially you are simply raising the front side bus in the bios, perhaps the voltage of the processor a bit. The are plenty of guides online. Here is a good one for beginners; http://www.pcstats.com/articleview.cfm?articleID=1804
It depends on the game, for example my E4500 would bottleneck my 4670 in C&C 3 when I go up against several Brutal AI.
Overall I don't think it's bottleneck it too much if you turn the settings up to high/very high and maybe AA.