You may as well sell/refund the 970 and get 2 390s rather than the SLI on the 970s, due to the fact that most games only recognize 3.5GB installed, unless forced to recognize the slower 0.5GB. Games can lose up to 50% performance if they begin using over 3.5GB. However, the 390 offers the same performance, and in some cases, slightly better performance, and 8GB of VRAM, and is slightly cheaper than the 970. They also don't require a 30 dollar tethering bridge, as they tether through the PCI-E ports, which have INSANE bandwidth. So you save some money, and squeeze better performance out of them, and can get even more if you choose to overclock.