SLI, most definitely. ATI has yet to come out with a dual card setup that is complete IMO, and to make matters worse every improvement has been via a hardware change. Anyone that bought an X850XT Xfire rig banking on the fact that ATI would iron out the issues in the future only got it half right. ATI fixed the issues, but not for their setup. Support IMO is the next thing right after price and performance. Don't get me wrong, I'm not saying that ATI doesn't support their products, but by design, Xfire makes it difficult for them to do so.