What is the best graphic card for my system?

[haohero]

x2 555
Biostar A780L
a 500w power supply
I have been using the onboard graphic card for a while and have decided to buy a graphic card. I don't want to buy the best graphic card but rather a good enough graphic card that my CPU will not bottleneck it. Tks in advance.

 

[StrangleHold]

What brand and model power supply and how much you want to spend?

 

[haohero]

Cooler Master 500w eXtreme power. As cheap as possible, around 150 to 200 bucks.

 

[StrangleHold]

6870 or GTX 560

 

[haohero]

My parents just cut my budget. Now I can only afford about $130. I am looking between 6790 or 550 ti. Which 1 is better?

 

[StrangleHold]

6790

 

[Casey]

But the 6870 would definitely be worth pulling off the 60-70 extra bucks.