I will be getting a 2500K in the near future, and want to pair it with a GPU upgrade at the same time. I have no experience with crossfire, and have always heard that the 5800 series scale very poorly. I was hoping to get ideas from those who have used both single 6900 series cards and dual 5800 setups. Any card I decide on will also require another $100 investment for a water block, which would make a 6970 be considerably more dough. Also, it is likely that I would have to scrounge a reference 5870 off of eBay, since vendors don't carry them anymore, and most water blocks only fit reference models. The main purpose for the upgrade will be BF3.