If this is the case that person will not be able to add a second card as its likely to be slightly different than the card already being used. SLi will only work with the exact same cards thats why i went with crossfire because with this you can use different cards. I wouldn't go SLi, but crossfire, yes.
hrm i don't think they have to be exactly the same, i've heard they just have to have the same core and clock speeds.. i'm pretty sure it would still work, but probably not 100 percent of what it could be
yeah thats true, only same model and clock speeds, as for crossfire you can use any 2, but SLi is proven to be better than crossfire. BUT THATS NOT THE POINT. you dont need SLI/Xfire. dont waste ur money on it.
If you're willing to wait, you should opt for Intel's Core 2 Duo series when it's released this summer. Their $200ish chip can trump AMD's $600ish chip, easily.
there u go again with SLI/Xfire WILL be needed, no they wil not, anytime that a newer game comes out that demands more there will be newer graphics cards that can single handedly handle a game, e.g. G80s, or ATi R600.
Yeah but obvlivion is out right now and the 7900GTX can maybe only just be able to play on highest settings or not even that and theres not better card out. So SLi/Xfire would be needed for that if you wanted full settings with good fps. Yes there will be a better card coming out soon (G80/R600) but then when a new game comes out when they are out they might struggle just like a 7900GTX does with oblivion. With SLi/Xfire you dont need to worry about it and saves you money on an upgrade every year.
and just to add on to that.. i would love to see a single card play in 1920 resolution.. some people have HUGE monitors and HAVE to play with 2 gpu's if they want any sort of good quality....
and to get back on topic, g.skill ddr 500 ram is excellent, it suites me just fine, i run a 1:1 ratio and not a single hickup running ddr560.. excellent ram for a bargain