5770 in crossfire would be MUCH better. I didn't even know 5830's still existed, at least not in Australia, they were a flop. If your going to get a better single card, get a gtx460. faster and uses less power than 5830. If I were you i would get the 5770 for xfire, or another cheap 5750 for xfire. That should keep you going for a while. Keep in mind there are a couple games that dont officially support xfire, so look at the games you want to play and do some research before going the crossfire route.