Has anyone here tried this:
https://hardforum.com/threads/asus-pike-is-usable-as-pcie-x4.1781277/
?
Unfortunately, the pictures are gone, but I assume something like this
http://www.ebay.com/itm/PCI-E-4X-to-4X-Riser-Card-Extender-Express-Extension...
and a low profile card are required.
In any case, an extra PCI-e x4 slot may come in handy. :-)
Christian