I am looking into just released Asus X99-E WS motherboard which is fantastic piece of engineering for an ultra high-end rig. One question just popped into my mind: Why the number of PCIE slots is limited to 7? 7 slots is of course a lot but the point is that 8 would be even better for some applications (2x4 sets of cards). Moreover, it seems that one slot is intentionally left as a PCIx16-only while certainly it could be made shareable with yet another slot into 2x8 configuration like it is done with the other slots. So it looks like adding the 8th PCIE slot would be a piece of cake and the price would not be a major factor in a so expensive motherboard. My question is thus if the decision to limit the number of PCIE slots to 7 is due to the limit on the size of the motherboard or due to some other technical issues?