Is there any difference performance-wise of having say Two Radeon HD 5870's in CrossFireX as opposed to having a single Radeon HD 5970? (Two HD 5870 cores on a single PCB) The Dual GPU card probably consumes much less energy than Two seperate graphics cards in a CFX setup of the exact same GPU type. The Radeon HD 5970's throughput is so massive, that even the PCIe 2.0 x16 bottlenecks it. A single slot, anyway. It isn't a major bottleneck, at least not until the next generation of graphics cards are released, with PCIe 3.0 x32 to go with it. It also costs less to buy the dual GPU card than to buy Two of the same GPU type. Two HD 5870's is $800 while an HD 5970 = $700.