What Are Slimline SAS?

I purchased a motherboard which comes with “Slimline SAS” without any further elaboration as to what that means anywhere i.e. what the connector is actually called and I cant figure out two things:

1.) Are these SFF-8654? Or are there multiple slimline codes? I only managed to find SFF-8654.

2.) Can you plug these directly into an SFF-8087 connector on a backplane (with the use of some converter cables of course for example https://overallcable.com/product/sas4-0-slim-line-sff-8654-to-sff-8087-internal-mini-sas-cable/)?

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It is complicated, and some boards have a slimline SAS connector, but only work with SATA drives.

If you give the model of the board , I’m sure someone will be able to give specific advice.

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@Trooper_ish yes, I’m reading that a SATA controller won’t work with a SAS backplane. The motherboard and case in question are

Gigabyte MS03-CE0 MS03-CE0 (rev. 1.x) | Server Motherboard - GIGABYTE Global

and

Inter Tech 4U-4724 4U-4724 - Inter-Tech Elektronik Handels GmbH

Respectively. I’ll be using SATA drives.

Right, you might be okay, maybe.

I have a similar case, and my backplane also uses SFF-8087

My case takes both SATA and SAS drives, but the backplane, like yours, does not have an “expander” so I am able to use an SFF-8087 “Reverse” to SATA cable, connecting the “SAS” socket on BP to the SATA headers on my motherboard.

I think you might be able to do the same, but with the sata only slim-sas, but wait for confirmation from others / google

Thanks I’ll wait for additional confirmation but I’m leaning towards it won’t work. Looking for these cables, I’ve uncovered a serious shortage in options. There are SFF-8654 to SFF-8087 cables but they are few and far between. Searching for reverse versions yields no results. There must be a reason for that. Hmm, I wonder what case Gigabyte was thinking of when they added 12 native SATA ports on a server motherboard!

I’ve not seen any of those cables in the wild, so can’t speak to them.

The backplane seems fine, the connectors on the board…

I literally have not used the slim SAS, only used the mini SAS.

Perhaps @aBav.Normie-Pleb might know?

Here I come rambling:

  • SlimSAS is just a name for a connector type similar to USB-C

  • SlimSAS comes in two flavors, with 4 lanes (SFF-8654-4i) or 8 lanes (SFF-8654-8i)

  • SlimSAS ports can be used for: SATA, SAS or PCIe (NVMe).

  • According to the specs page of that motherboard it uses SFF-8654-4i ports for SATA only, each can handle 4 x SATA with adapter cables.

  • Yes, you can use an SFF-8654-4i-to-SFF-8643 adapter cable to connect a SATA backplane to that motherboard. Note: Most backplanes with that many drive bays use a SAS expander chipset internally to reduce the amount of cables they need to connect to the host. In this case you would need an additional SAS HBA to use that backplane, even if the drive bays themselves only support SATA (think of SAS expanders as something similar to nework switches but for SAS and SATA drives).
    Example for a passive SATA backplane that could be used with the mentioned motherboard: MB924IP-B_Rugged 24 x 2.5" SAS/SATA HDD/SSD Mobile Rack Enclosure for 3 x 5.25" Bay (6 x Mini-SAS HD) (when looking at its back you can see one SFF port for every 4 drive bays).

  • If the intended 24 port backplane has less than 6 SFF input ports then it is using a SAS expander chipset and would be incompatible to directly connect to the motherboard without an additional SAS HBA.

  • Maybe, depending on the motherboard design and BIOS: You might be able to use the SFF-8654-4i ports for PCIe/NVMe, but that’s uncertain.

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Thanks for the responses guys!

Understood, so this to me means that it should be possible to get a reverse breakout cable and it should work? But given your later point about the fact that SAS backplanes use internal chipsets would mean this wouldn’t be possible.

From what I’ve seen, backplanes with internal chipsets usually have a heatsink. There are actually two backplanes in that case, which support 12 drives each and don’t appear to have any heatsinks on them, so maybe they are dumb backplanes?

This next image however shows that there is a chip. Not sure if that’s a chipset however.

Sorry not sure where you got SFF-8643 from? The backplane in that case uses SFF-8087.

Sorry if I have given incorrect information.

I have several SFF-8087-to-SFF8087 regular cables, between HBA’s and the backplanes

The reverse cable, was from my backplane, SFF-8087-to-sata on my motherboard.
Because one motherboard did not have enough PCIE sockets to run HBA’s

I think a regular cable will probably work for you, between motherboard and backplane, but again, I have not dealt with this slim-sas connector, even though the sockets look to have been around a while.

Also, like Normie said, there are 8- wide and 4- wide connectors; the wrong one will not fit…

Had a brain fart, possibly since I personally only ever used passive SATA backplanes with SFF-8643 ports, never with SFF-8087.

That thing looks indeed like a non-SAS model.

Note: “Reverse breakout cables” are only needed if you wanted to connect such a SATA backplane to a regular motherboard that only has normal individual SATA ports.

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Each backplane has 3 connectors for 4 drives each. You need a SFF-8087 → HBA cable for each of those. HBA with 16 ports can accomodate 4x4 drives. So you need an HBA with 24 ports or two HBAs to get all the 6 cables going.

The HBA itself usually has SFF-8087/8088 or 8643 connectors. Unless you want to plug the drives into SATA ports, in which case you need reverse breakout cables and good cable management skills :wink:

or connect to a HBA that has SFF-8087 (older Broadcoms have these I think, like 9100/9200 series)

With a Broadcom 9300 series which has 8643 connectors, you want this one:

But they’re cables…any brand will do. Just don’t go too cheap on cables.

My reasoning is simple, if these are just SATA breakout connectors, then logically (at least to me), it’s like running a cable from the backplane to the SATA ports on the motherboard.

Hmm.

I guess it won’t hurt to try. I’ll buy one cable and if it works, great and I’ll get two more! Otherwise, I’ve got enough PCIe slots to just get HBA cards.

@Exard3k I’m trying to figure out how to connect that backplane to a motherboard with some Slimsline SAS connectors, not to an HBA. My motherboard supports 12 SATA drives from connectors on the motherboard itself. Might as well make the most of them if at all possible.

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Yep, understand, thanks!

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  • Maybe an important note for the future: When I’m describing cables I always go from the host/computer to the target/drive.

Examples:

  • An SFF-8654-4i-to-4xSATA cable would be needed to connect 4 individual SATA drives to the Gigabyte Server motherboard that has been discussed in in this thread

  • BUT you can’t just turn this cable around for the case when you want to connect a passive SATA backplane with an SFF-8654-4i port to a “consumer” motherboard that has individual regular SATA ports.

  • I don’t know if this “just” doesn’t work or if you could cause physical damage to anything.

  • I’ve been using such reverse-breakout cables (4xSATA-to-SFF-8643) with a consumer motherboard and an Icy Dock 8 x SATA backplane and taped warning labels to the cables used here to never accidentally use them the other way around.

  • I’d be happy to be confirmed or corrected if someone has specific knowledge here regarding the danger or maybe non-danger of such inverted configurations regarding permanent physical damage.

This does SlimSAS on the MB to individual drives (no backplane needed):
https://www.amazon.com/DiLiVing-SFF-8654-SATA,SFF-8654-SFF-8643-Controller/dp/B087TD48X4

This does SlimSAS to the backplane connection for the one you linked aboive:

This is SlimSAS 8i (your MB probably has 4i) and goes to two backplane type connections. It may not work, but it might end up working with only 1 of the 8087 cables functional:
https://www.amazon.com/ChenYang-SFF-8654-Ultraport-Slimline-PCI-Express/dp/B09Q64DHV6/ref=sr_1_4?crid=18PDDHNRS1ZQW&keywords=SlimSAS%2Bto%2BSFF-8087&qid=1695134444&s=industrial&sprefix=slimsas%2Bto%2Bsff-8087%2Cindustrial%2C162&sr=1-4&th=1

edit months later: looks like Amazon is being dumb again cause the seller has a new item and by listing it is screwed up the last link so it goes to a different product now. At least that was the lest likely cable for you to want. Dont know how long the other links will work properly.

OP wishes to connect from SFF-8654 to the mini SAS connector, SFF-8087

But thanks for a link

He wrote he wants to connect drives in a SFF8087 backplane to the 12 SATA ports on his board. In which case reverse breakout is the correct cable. 8654 obviously is wrong if the backplane has 8087 connectors

His board did not have traditional sata ports, only the slim SAS connector?

The backplane does indeed have (several) 8087

I appologise if my reference to reverse cables muddied the waters.

I myself used a mini-sas-reverse-to-sata for my own backplane to connect to my motherboard, at one time, before I was able to run a board with enough HBA’s

OP’s proposed board lists connectivity as:

SAS
N/A
SATA
3 x SlimSAS with 12 x SATA 6Gb/s ports

I personally don’t have experience with the slim SAS connector, and whether it would need a forward, or reverse.

Hi,

I own a SC846A backplane and while shopping for a new motherboard did some google searches that lead me here.

The new motherboard I’m considering can present SATA lanes over MCIO ports (after toggling a BIOS option).

I think I may have found the cable that I/we need ?

h**ps://www.alibaba.com/product-detail/PCI-E-5-0-Mini-SAS_1600838359792.html