Thanks for the speedy reply, ChumP !
But I am still confused.
Someone on this forum (Mffinn), posted the following:
Seems that default BIOS settings are just fine and this setup is actually OK. This motherboard does not get the maximum read speed from this SSD because it only has two PCIx2 lanes for the M.2 slot: http://techreport.com/review/28036/asus-z97-p-motherboard-reviewed