m.2 ssd replaces in bios sata_3 hdd what should not happen

[j.thomas.jelle8]

my m.2 ssd replaces my hdd but i want both in my rig to use i can only see one
i have bought a additional ssd i already had a hdd but when installed the ssd in a m.2 to slot it dind't show up in the bios or in windows i tried a different slot it works there but then i can't see my hdd
i can't have both til now

 

[Petrossa]

Some M.2 interfaces share a data lane with the corresponding SATA port.
Check your motherboard manual for which to use, and which combination you can use them.