Affordable Mobo/Processor Upgrade!

[zex_vex55]

So I recently got a new graphics card, and it wasn't performing to its maximum potential, I was told it could be my processor holding it back, as mine is a bit outdated. How much do affordable processors go for? Would I be able to just get a processor and be fine, or a whole new mobo?

specs:
AMD Athlon Dual Core Processor 4050e 2.10 ghz
400 watt psu
3GB Ram
ATI Radeon 5670

Mobo:
HT2000
MCP61PM-GM

Thanks!

 

[zex_vex55]

ATI HD Radeon 5670