HBA/Raid Card for U.2 Drives

I bought two U.2 drives to add to my desktop (mini-workstation). What kind of add in card can I use to connect them? I have only a x16 slot and two x1 slots open.

Long version
I built a ryzen system this Black Friday for web browsing, gaming, and light video editing. But I needed more storage. I have my 2 m.2 slots filled with a 1tb and 2tb drive. I have 2 x1 slots and an x16 slot open. I want to add a RAID/HBA card with 4 ports so I can add another 2 drives in the future. I would like to use a cheaper card RAID card off ebay

I know they have dedicated NVMe RAID cards now but would there be that big of a performance difference? Any information will be helpful. My google-fu has failed me.

Reserved for edits

What board? Cuz that 16x is probably only 8 lanes at most and those 1x are probably sharing with your 1 m.2 already

You will need a card similar to that one at the end of the day, but if you are using this much PCIE you probably should go ThreadRipper
Or 2nd storage box you have 10gb connection to

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Asrock x570 Phantom Gaming 4

I would love to add a 10g nic instead to another box (NAS) but that will have to wait for next years tax return.

3xxx cpu? Honestly it will need to go into your 16x slot, and need to be an HBA like the one you listed on the plus side you can move it to a nas later.


total bandwidth will be limited to x8 lanes tho

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of guessing pcei gen 3 (looking up that chip now)

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U.2 isn’t SAS or SATA, it’s PCI Express. A x8 to dual nvme card and two m.2 to u.2 riser cables is what I’d go with.

Unless I’ve missed something?


Agreed the SAS controller won’t work with NVMe. You would be better off using sata SSDs for that.

As far as I am aware there are only a couple of add in HBAs for NVME, such as the HighPoint SSD7120. They are not cheap.

I agree with @gordonthree you would be better getting a m.2 add in card that either raids the drives or supports bifurcation (if your board supports this) and use m.2 to u.2 cables.

There is potentially another problem. So far I’ve only seen bifurcation to split a x16 into chunks of the same size. The most obvious being x8x8 over two slots. My X470 Taichi Ultimate also has a x4x4x4x4 mode. BUT it can’t split unevenly. So the theoretical perfect layout for a GPU and two storage devices x8x4x4 isn’t possible.

Again, just wanted to throw that out in case it’s the same on other boards as well because that is how it works on my X470 board.

Others raised this so only short add-on. NVMe U.2 communicates via SFF-8639 connector. On paper it looks identical with SFF-8643 mSAS, but pin-out inside is completely different. Do not connect U.2 device to normal mSAS connector. At best it just won’t work, at worse you can damage both devices.

Recently OWC released Accelsior 4M2. In US you shouldn’t have problem getting just the card without drives. x8 4 slot M.2 with PLX switch. Very reasonably priced. Does not require bifurcation from motherboard although software works only on Mac, setting up RAID in Windows is not a problem.

You might find some tips here:

If you’re referring to my recommendation…
It does all 3.

Additional adapters would be needed for the m.2s but you aren’t limited to them either.

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Supermicro has two cards that might help, one with a PLX chip, and one without.

Supermicro AOC-SLG3-2E4R
Supermicro AOC-SLG3-2E4

The PLX version should work for you, probably. The non-PLX may or may not.

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That card has some sweet specs!

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Wow all! Thanks for the quick replies. I have to get up at FML dark thirty in the morning so I’m just now able to respond.
Looks like my mobo doesn’t support bifurcation. I’ll need to pick up an add in card u.2 carrier for one drive and hold on to the other for later.

I understand its PCIe, I just was trying to find out how they can interface with your board without u.2 built in. I saw a lot of these cables online.
Vorlon, Thanks for link. I’ll keep this in mind, I may have to move my m.2 drives to a card like this and then use an add in card for the u.2 drives.
Trooper_Ish, I’m a servethehome fan, I didnt get that far back in time in my own research. Thanks, I saved a copy of the article for future reference.

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There really doesn’t seem to be much information about how to connect U.2 drives to desktops aggregated in one place. I’ll keep researching and see what I can come up with and test with my drives. I may be able to make a short how-to for the forums.

Mostly because u.2 aren’t intended for desktops. Only thanks to Facebook and others dumping old drives on eBay are they even accessible to the average Joe. Avg Joe can’t benefit from u.2 either, a desktop user doesn’t generate the workload to take advantage of those drives, and their baseline throughput is pretty poor compared to cheaper m.2 drives.

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I may not have the workload for u.2 but I need the space. I got a pair of Sandisk skyhawk 1.92tb drives for $150 each. Any m.2 drive would have been at least $200 each. I really just don’t like to but spinning rust unless its for a NAS. Every disk drive I buy seems to put out a whine to my ears.

Anyone seen something like this used?

Theres also this:

and the LSI/broadcom 9400-8i and 9400-16i

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