Looking at the photo with the second GPU, there seems to be another PCIe slot in front of it at the bottom. They show a shot of a card inserted in front of one, but if you look at the other one, then you see what looks like another white slot. Maybe that is why they are saying 1.25GB/s read and 1GB/write. In a Raid 0 array, that is the kind of speed you can expect from current SSD tech. Which makes sense, otherwise, where is Apple getting this insanely fast SSD from?