As people already know they are physically compatible, you can plug an M.2 SATA (aka M+B key) into an M.2 NVMe (M key).

My question is will it work?


  • 1
    What motherboard are you using? – AdmiralFreebee Mar 14 '18 at 9:42
  • 1
    According to wikipedia M keyed means "PCIe ×4, SATA and SMBus". So a M-keyed M.2 port can do both PCIe/NVMe and SATA. – Hennes Mar 14 '18 at 14:24
  • @Hennes Interesting, so that would mean yes... In theory an M.2 NVMe equipped Macbook Retina could accommodate an M.2 SATA drive. – unom Mar 14 '18 at 17:14

A slot that can do SATA will have the M key and/or B key.

A slot that cannot do SATA will not have either the M or B key, but others instead, making it physically impossible to insert a SATA-only card.

A card with multiple keys can only use the lowest common set of features. With B+M, that’s PCIe x2, SATA and SMBus.

Because an M.2 NVMe SSD typically wants PCIe x4, there’s only one possibility: M key.

It might be noteworthy that slots with multiple keys are very rare, if they exist at all.

If a card physically fits the slot, it will work. That’s the entire idea behind the key notches.

  • Corrected the type I meant M+B key versus just M key. this is the case I described. In this case one can insert a M+B key drive into a just M slot it fits. The other, connecting a M key drive to an M+B key slot is impossible. – unom Mar 14 '18 at 12:54
  • @unmircea I updated my answer. Please accept an answer if it answers your question. If you need further clarification, please let me know. – Daniel B Mar 15 '18 at 11:19
  • In Asus laptop, Q534UXK is possible to connect SATA m.2 or PCI m.2. but the motherboard has a label with the two options! – RckLN Sep 11 '18 at 3:20
  • @Daniel B, I agree this doesn't seem to answer the question. An NVMe has an M-key only, while many SATA's seem to have B+M, and so will physically fit in an NVMe slot. All your answer seems to say is that a SATA device without an M-key won't fit. – Matthew Jun 10 '19 at 21:18
  • @Matthew An M-keyed slot also offers SATA. I don’t see the problem? – Daniel B Jun 10 '19 at 22:07

Just because an M only slot fits into M+B slot does not necessarily mean it will work.

Here is an example : M-Slots for M+B and M only


NVME drive uses pci-e signal, while SATA m.2 still uses SATA signal. They are quite different. Most ssd enclosures only support either one protocol, while most motherboard m.2 ports usually support both standards at same time. (There are some exceptions.) If your port is m.2 b+m, then you can only use sata m.2 ssd. If your port is m.2 key m, you should be able to use nvme ssd, and you *might* be able to use sata m.2 ssd.


Support for NVME is largely determined by the BIOS. For a motherboard with a m.2 slot, it can work with m.2 SATA SSDs that usually have the B and M cut-outs and the slot normally has only the M key on the right side. A m.2 NVME SSD will slot in but usually won't work unless the BIOS has an option to set the m.2 slot to either SATA or NVME. If a motherboard has a m.2 slot and was made before 2016 it's unlikely to support NVME, but check your motherboard manufacturers' website for a BIOS update that may add support for NVME.


I just bought a new replacement SSD on recommendation from a PC retailer who offered the correct option for my laptop without me knowing anything about what Slot was in my laptop. I received a new NVMe m slot SSD HD but when I opened my laptop was alarmed to find it fitted with a SSD HD with an M+B slot in it.
I scratched my head a little, took out the M+B Sata Drive and the NVMe M only slot drive straight into the existing port. flipped it over and expected nothing but Bios errors. To My suprise the NVMe M slot Drive worked perfectly. hope my experience helps someone

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.