1GB is a waste on a 4670. Get the 512MB version on Newegg that I saw for like $36 USD after mail-in rebate... You can get an HD 4850 for $100.
What he said. If your PSU is weak though, the 4670 is attractive, as it is powered entirely off the Mobo, and is rather stingy with it use of electricity. With that CPU you could definitely get a lot more game for your buck with a 4850, provided your PSU isn't a dodgy low power no name brand unit.