I've been eying the HD 3870 for a few months now, and have recently discovered the awesomeness of the 4870. And after looking at prices, it seems like I could get two 3870's in crossfire mode and it would be slightly less expensive than buying one 4870. Now I'm not sure if there are any big disadvantages to using two cards in crossfire mode compared to using a single better card. But the two 3870's would have a combined ram of 1gb and a memory rate of 512mb. There's also the fact that the 4870 has 800 stream processors compared to the 3870's 320. I'm not sure if that is more important than having more memory or not. I'm kinda leaning towards the HD 4870, but I just wanted to be sure. And I suppose the 4850 is always another option, but GDDR3 seems like a big disadvantage.