As I stated in another thread, I live in an AGP world and am looking to cross over to PCIe. Now, I'm naturally assuming that the 16x is going to be faster, and my new cards will be going towards an SLi setup. But, on some motherboards I see that the PCIe "speed" changes based on whether you run SLi. This confuses me somewhat. I have seen where it changes from two 16x to 8x/8x, I have seen two 16x change to 16x/1x. I do not understand these "measurements" at all. Is there any motherboard that will run PCIe as 16x/16x if you have two 16x cards? Or is that simply a wishful impossibility?