I just recently bought the ACHI version of the sm951 and I can't get the laptop to recognize it either.
Here is a link to what I bought:
http://www.newegg.com/Product/Produc...82E16820147425I've been on with Asus support multiple times and the latest time they gave me the following instructions:
1. Go to BIOS >> Advance Settings
2. Change SATA Mode to IDE/AHCI (backward compatible) in PCI Storage Configuration
3. Set SATA Support to All Devices
4. Enable CSM and set
Boot Device control: UEFI and Legacy OPROM
Boot from Storage Devices: Legacy Only
Boot from Network Devices: Legacy Only
Boot from PCI-E/PCE Expansion Devices: UEFI Driver First
5. Disable Secure Boot (Set to Other OS)
6. Set Booting Order: 1st priority M.2 SSD 2280, 2nd DVD-ROM
7. Install Windows at selecting disk step, at drive option, delete any partition of M.2 SSD
If the M.2 SSD is not showing in the BIOS then you will need to try a different M.2 SSD.