Is it possible to SLi 2 different cards? IE 1 8800GTS and 1 9800GTS(even though it's not even out yet), Would that be possible? Or how about a 7900GS alongside a 8800GTS? I'm just asking so if i were to get a card now, and when the 9800s come out i could get one of them and throw it in along side my current.. thanks