Which is it ?
Number 1 does not actually have a "hole/plug" for the nvme to go into.....there is no 'hole' in the board.
Number 2 does have a plug to push the nvme into
It's rather economical for motherboard manufacturers to produce nearly identical boards... just adding options on different models to increase the price. I think you can see this pretty clearly with your board, Brian. Scroll down to the Slots and Storage sections on links below for details.
ASRock B150M Pro4
ASRock B150M Pro4/D3
ASRock B150M Pro4/Hyper
(the only one with a M.2 socket included)
I'm not very up-to-date on "modern" hardware, but it's worth reading up on the technologies that you are pursuing, and Wikipedia is usually a good source.
The Wikipedia info reveals that NVMe devices can be packaged in several form factors, including PCIe and the M.2 SSD type that you show above. And specifically, that is a "M key" edge connector (with 5 pins on the short side) in your picture.
Will you need an adapter to use the M.2 NVMe drive? Absolutely. I don't like using adapters, but sometimes they are necessary. And which one? (That's why I don't like them!) I would only say to be sure that both connections, M.2 (M key) and PCIe, will match (or be compatible with) your system.
Just for a couple of examples (that may or may not match your system)... here is one
that stays suspended in the PCIe socket without any mounting hardware to hold it in place. This should be fine in a desktop that doesn't get bumped around since these edge connectors are quite snug. But this one only has a 3.5 star rating with very few reviews, though it's cheap and it looks like it would fit the socket in your pictures. Here is another
with 4.5 stars and many more reviews, but it is designed to reach from your PCIe socket to the back of the case for better mounting. Here's one more
designed to reach the back of the case for mounting.
This is the adapter
you listed in your first post. It shows unavailable to me, but maybe because I'm not in Australia? Anyway, please do note the difference in the PCIe edge connector. That is totally different
from the picture you showed us. The ad says this is a PCIe x4 edge connector.
Lastly, let me remind you of this:
Also in the specs, there is a red asterisk beside
- 2 x PCI Express 3.0 x16 Slots (PCIE1: x16 mode; PCIE4: x4 mode)*
- 2 x PCI Express 3.0 x1 Slots (Flexible PCIe)
- Supports AMD Quad CrossFireX™ and CrossFireX™
*Supports NVMe SSD as boot disks
Again, your adapter must match (or be compatible with) your system, and this bit is telling us that not all of the PCIe slots will work to boot your NVMe drive. Look over your board again carefully, check the user manual if it will help... but try to be sure which PCIe is the one that supports NVMe, and match that connector when you buy an adapter.
Your specs show 2 each of PCIe 3.0 x16 and PCIe 3.0 x1. As I'm digging on the internet, the x1 is the shorter socket you show in the pictures, and that likely will NOT
boot your NVme. The adapter that I linked to above, the one that just stays suspended in the socket without mounting hardware... the ad for it says that it will fit in x1, x4, x8, or x16 sockets. That's encouraging. Watch for that as you shop around... you need the adapter to be compatible with the x16 socket (slot) on the motherboard and the M.2 (M key) NVMe. By the way, PCIe 4.0 is backward compatible with PCIe 3.0, if you notice that while shopping.
[EDIT] But wait, there's more!
Take a peek at this article
. It explains the difference between x1, x4, x8, and x16... the number of data lines. Your NVMe may boot in either Slot 1 (x16 mode) or in Slot 4 (x4 mode). The slots will look the same, I think, but I would guess here that Slot 1 (x16 mode) is the preferred one. More data lines = more speed... maybe. In truth, though, it may not make a difference which one you use of these two slots. [/EDIT]
I hope that helps. Good luck!