pezonator :
Hi there!
We really need more details...
What is your budget and what are your other system specs like power supply, ram, motherboard, case?
No one here would ever recommend upgrading from a 3470 to a 3570k. If you can, going from a GT640 to a GTX660 would be a huge upgrade, but then it all depends on budget and power supply specs and your overall computer build (is it a dell etc).
Intel core i5 3470 @3.2Ghz
Nvidia GT 640 2Gb
Gigabyte GA-B75M-D3H
Kingston Hyper X 8gb DDR3 @ 1600 MHz
1TB WD Blue
3TB Seagate
700 WATT OCZ ModXtreme Pro PSU
My specs^ its a custom build and my budget is around $250 maybe a little bit more, no more than $300
BTW; any suggestion on what I could/should upgrade?