O.C.ing your CPU would help but you would have to get to around 3.3ghz or 3.4ghz to lessen the bottleneck for a 6850/6870.Honestly though I think the 6770 fits perfectly with your CPU and PC.The Twin Frozr II is a great card.
well i might just stick with what i have and go with the 6770 and also is the power supply needed cause i was planing on getting more ram so and maybe even i new fan cause this thing only has 1 and what games can i play with the 6770? thanks
Yes you absolutely need a new PSU.The HP PSU that you have doesn't have enough power to supply a 6770 and the rest of your system.You get a $15 MIR from the Twin Frozr II.But if you wanted to save more money for RAM you can get a cheaper 6770 and a cheaper PSU.But you already have 4G of RAM and I don't think you would benifit from more.
Honestly I would put your money towards a new case then new RAM and a new fan.Those HP Micro Case's are horrible for air flow and are really small.Also I had 4G of RAM and upgraded so now I have 8GB and I really don't notice much of a difference at all.