I have done a lot of searching but still cannot get a clear answer on this.
My motherboard is a ASUS PRIME B250M-A which has an M-Key (Socket 3) connection.
I want to add a WD Blue 3D NAND 250GB WDS250G2B0B drive to it which has a B+M key (Socket 2).
It seems like it is not compatable, but according to this WD document it is?
That board only supports Sata drives in one of the two M.2.
It will work so long as it is in the correct M.2 and they state on the motherboard what they support with a V/Y for yes and X for no.
So top slot will support Sata and PCIe but not IRST which is OPTANE, Bottom slot will support PCIe and IRST/OPTANE but not Sata.
You need to use the top slot with that drive.
Yes, this SSD is compatible with this mobo, according to the mobo manual.
Specifically, this is an M.2 SATA SSD. And this mobo has two M.2. slots. M.2_1 slot supports both SATA and NVMe ... so plug this SSD into it. M.2_2 slot only supports NVMe, so it will not work in that slot.
Note, when you use M.2_1 in SATA mode, this will disable the SATA port SATA1--so if you are also plugging in a normal SATA drive (like an HDD or 2.5" SDD) then be sure to use SATA2 thru SATA6, and not SATA1. You've got plenty to choose from.
Thanks for the clarification. This is starting to make sense. So, if I bought the 970 Evo, then I would use the bottom slot (M.2_2).
Yes. A 970 Evo could be used in either M.2 slot (M.2_2 or M.2_1). M.2_2 only supports NVMe, while M.2_1 can support NVMe or SATA.