I got an Asus ROG Z270i board, love it but the only problem is the M.2 on the back of the board seems to be capped to SATA M.2 which has greatly fallen in popularity to NVME. Would it possible for me to put a NVME M.2 on the SATA M.2 slot on the back of the board and have it work (albeit, at greatly reduced speeds)? I'd be willing to do this until I could upgrade the board.
I find it very strange that Asus decided to go with this setup as I thought the Kaby Lake Series of chips had 28 PCIE lanes available so the GFX card would take x16 and the other two NVME's would take x4 each respectively. Not sure what kept them back from this.
SATA supports RAID/ACHI/IDE but not NVMe. You'd need to use the front one if the rear one is SATA.