Will a M+B key M.2 8x Sata card work in a M key socket?

Hello all! I have been looking to build my own NAS and have it all figured out but have run into one small potential issue.

I am planning to put this M.2 to 8x Sata card;

Onto this MB;

But am a bit confused. The M.2 card says it required a M+B key M.2 slot. But I thought that M+B keyed cards worked in M keyed slots. Is there something I need to be aware of? Dees the M.2 slot also have to have Sata support? or will it just worK? I can’t seem to get a straight answer.

Generally speaking a B+M(male) key does not work in a M key slot(female). You must use a B+M female slot. However, you can plug b or m key into a b+m female slot.



Source: M.2 M vs M.2 (B+M): What's the Difference? - MiniTool Partition Wizard

But your link literally says that a M+B key can work in a M key slot….

“an M.2 M key slot is compatible with both B+M key SSD and M key SSD.”

So again the question is does that M key slot also have to support Sata???

What I have been also wondering as the M.2 card is M+B Key is if it’s a hybrid Sata multiplier and that’s why it may need the Sata as well as the PCI-e from the M.2 slot…

Again to straight answers…


It should work in M.2 M key slot just fine.
B+M key can support either SATA or PCIe.


However, unless you really need 8 disks, I would recommend looking at ASM1166 based adapter.
This one seems to use JMB585, which has 5 sata ports.
I looks like 4 are accessible on the first connector, and the remaining one is split with a multiplier to another 4 on the second connector.

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I do intend to make a 8 bay NAS using the Jonsbo N3 case, I have looked around and found a M.2 E key to 2 Sata card as well and a M.2 M key to 6 Sata card using the chipset you recommended but I was kinda planning to use the E key slot for another Ethernet port… same for the PCI-e 1x slot on the MB…

But I thought that M+B keyed cards worked in M keyed slots.

Sorry I may have misread your question earlier. Sounded you were saying that the device was B+M (Male) going into an M (Female).

You can plug an M, B, or a B+M (male) connector into a B+M key slot(female). A B+M (male) cannot go into a M(female) most of the time(however I would not be shocked if some devices supported this) I would see the image posted by @Oem_Test above to see the differences.

Yes, the M+B card (male) going into a M slot on the MB (female)

But from what I read LONG again this is not an issue. M+B can work in EITHER M or B key slots. The male side is a subtractive notch and can physically fit in either the M or B key slot.

The part that I was hung up on is that the Card page said it REQUIRES a M+B slot that to my knowledge does not exist?

So my thought process was that perhaps it’s just a Sata multiplier (so using the B key portion for Sata) with a control interface over PCI-e (the M part) and I’m still wondering if that’s the case…

I don’t think it’s the case. It doesn’t look like SATA and PCIe can be used at the same time, as they share the same pins:
CONFIG_1 pin enables the appropriate host interface:
• CONFIG_1 low enables SATA
• CONFIG_1 high enables PCIe

I think it will just work. But I don’t know, how well. :slight_smile:
Everywhere I looked, when I built my own system, SATA multipliers were not recommended:

The m.2 slots on pretty much all n100 boards are only 2x 3.0 lanes

Idk if those SATA m.2 cards will work under that or not

The M.2 card is only 3.0 x2 anyways

I’m not actually sure it is a multiplier, from what I can tell from this product Picture; and the general layout of the PCB I think it’s just two of the Sata controllers each using 1 PCI-e lane and just dropping the 5th Sata port on each

Edit: Ah never mind, looking up the card from the actual manufacturer IOCrest it is a port multiplier

Edit 2: however I’m now confused as even there 4 port unit using the same JB chip also says it supports port multiplier… so I’m just stumped now…

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I have sent an email to IOCrest asking what the topology of the card is, let’s see what they say.

Have you considered using the AsRock N100DC with an ASM1166 controller? That board has two SATA on board so you’re gonna need just a 6 SATA ports controller.

I’m suggesting the ASM1166 because it supports ASPM properly and I’ve been having good luck with it so far.

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Yes, but there are reasons that I am going for the Asus board (even though it does not seem to be on sale anywhere now…) such as having a 16gb DDR4 SODDIM lying around, that and the Asrock board only supports DC external power, and the manual of it say it only can support a maximum of 4 (even though it has 2 Sata Data) HDDs power wise. Also I technically need a total of 9 Sata ports as I need one for the OS, already have a Sata SSD lying around that fits the bill.

That Asus board fits the bill exactly with the exception of ECC RAM, (oh well) and an open PCI-e slot for use with larger cards even if still 1x

That makes total sense and because the AsRock board is DC power only I didn’t go for it.
It’s unfortunate that AsRock makes the non-DC version in mATX only. I decided to “make fit” the mATX board for my NAS but the Jonsbo case you chose can’t fit it even if you hacked it together somehow.

Not to shamefully plug my own threads but I’ve done a build log around the AsRock N100M, you might find it interesting since you’re going the same route: https://forum.level1techs.com/t/build-log-silent-night-my-own-take-on-quiet-and-power-efficient-nas/

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Yes that is very similar to what I have been planning, I was even debating at one point using 8x 8TB Sata SSDs in a Icydock 5.25 to 8x 2.5 adapter! (to expensive) The only Big difference between your build and mine (other than the SSDs) is I plan to use the HDPLEX 250W Gan PSU;

I have had one question about the N100 chip which since you have one can you confirm that it has AV1 Decode? It should from what I can tell as its alderlake but… it’s high on my wishlist per say.

I do Have a fallback that I would like to run past you all. If that 8x card does use a Sata multiplier I am thinking I will get these two card to compensate;

I cant seem to find any PCI-e 3.0 x1 Sata card that 8 Sata ports that does not use a multiplier…

I was hoping to use the E key slot for a 2.5g ethernet or Sata SSD cache but after looking around it appears I can get PCI-e 3.0 x1 to multiport multi gig ethernet.

Do the board and drive support the same protocol (NVME vs SATA)?
If yes, yes; if no, no.
That’s it

There are also CWWK NAS boards you may find interesting: