m.2 and sata

[kidmo87]

Hello, I am about to start mining, and am a little confused about m.2(adding extra gpu) and sata(for operating system). I have a z170-a, and in the user manual it says "The M.2 socket shares SATA ports with SATA Express. Only one SATA device could be activated." It also tells me to look in the bios section on how to activate it. But in bios section it says "SATA mode will be switched to M.2 SATA Express can only support PCIE devices".
Are they saying I can only use one or the other. If so, how can i install a HDD or SSD?
Thanks

 

[PP Mguire]

If you activate SATA on the M.2 port it will disable SATA for the SATA Express port. If you enable PCI-E for the M.2 it'll disable PCI-E for the SATA Express port.