Upgrading my CPU - expectations?

Currently using

AMD Athlon II X2 270 Regor 3.4 GHz 2x1 MB L2 Cache Socket AM3 65W Dual-Core
XFX - Radeon HD 6570 1GB DDR3 PCI Express Graphics Card
8 GB of Ram

I'm looking at buying a - AMD Phenom II X4 965 3.4Ghz

I'm sitting at around 20 fps on WarZ/Diablo 3, how much of an improvement should I expect? I know my GPU could use an upgrade as well, but I'm thinking the processor is the bigger bottleneck out of the two.

Here is a low TDP gpu that will allow you to play theese games at a higher framerate and settings.

ghz 7770

http://www.newegg.com/Product/Product.aspx?Item=N82E16814127664

Awesome, thanks a lot.

Do you have any opinion on this card?

http://www.amazon.com/ASUS-HD7770-DC-1GD5-V2-Radeon-GDDR5-Graphics/dp/B007RFYFH0/ref=sr_1_3?s=electronics&ie=UTF8&qid=1355948301&sr=1-3&keywords=hd+radeon+7770

There's one I can pick up in my area today for $130 so I was just curious.

but why would u pay moar? specifically 20 bucks moar??