pure_sandpike :
going to build a whole new gamer. was trying to squeeze a little more out of the old girl what about a radeon hd
7770
It's an improvement over the hd4890, but you're still going to be limited by the rest of your system. I guess in theory a better card will allow you to turn the settings up a bit, but you probably won't see much increase in frame rates as they are often limited by CPU power, especially in the newer games.
If you want to squeeze all you can out of your current system, you definitely want to upgrade your 4GB of RAM to 8GB....I'm assuming you're running a 64bit OS, because if you're not, then you can't use more than 4GB.
I checked and i am running 8 gigs of ram