It has an 800w PSU and already xfired 6850's so it has enough connectors but based on the description of the motherboard it sounds cheap and will bottleneck GPU's like xfired 6990's because it only has one PCI-E x16 lane. Also if you were going to go with dual 6990's I'd upgrade to a 1000-1200w PSU because they are really power hungry cards along with the i7 that's in the computer.

valdiston wrote It has an 800w PSU and already xfired 6850's so it has enough connectors but based on the description of the motherboard it sounds cheap and will bottleneck GPU's like xfired 6990's because it only has one PCI-E x16 lane. Also if you were going to go with dual 6990's I'd upgrade to a 1000-1200w PSU because they are really power hungry cards along with the i7 that's in the computer.

Yeah I noticed that that 6990 is very demanding in power so I'm thinking of crossfire 6950's. Do you think the motherboard would be enough to handle 2 6950's and the power supply?

It's not that the motherboard can't handle them its if the motherboard only has 1 x16 slot then the second card will run really slow making it almost not worth it to crossfire. Most motherboards that support xfire have 2 x16 slots that then scale down to 16x and 8x when cards are put in, other higher end like $300 boards have dual or triple x16 so they run x16 by x16 or x16-x16-x16. Those boards are really expensive though.

after thinking for a few minutes I think you should just scrap your idea for xfire. It really isn't needed and not every game is designed to make use of two GPU's games like wow and things that aren't crysis and BF3 can't even use the second GPU. If I were you I would go with a single 6990, they are extremely powerful cards and will easily run any game maxed with great frame rates.

valdiston wrote after thinking for a few minutes I think you should just scrap your idea for xfire. It really isn't needed and not every game is designed to make use of two GPU's games like wow and things that aren't crysis and BF3 can't even use the second GPU. If I were you I would go with a single 6990, they are extremely powerful cards and will easily run any game maxed with great frame rates.

Well this motherboard is: P67 Pro3 SE. It does say that it has 2 x PCI Express 2.0 x16 slots and supports ATI Crossfire, and Quad Fire.