Explain like I'm a toddler - Data cables

I’m a realtively light homelab user, so far all my builds have been unraid using SATA interfaces, cables, and drives. I’m brand new to all this SAS stuff, but would like to learn how it all works, but I’m lost in the weeds.

I’m looking at this chassis because its the perfect chassis for my new rack (not as deep as the current one, this chassis is shorter and has more features so its perfect)

I will be using gaming level hardware as I use Plex transcoding and a couple VM’s so the Xenon included won’t cut it for me. I’m looking at this motherboard:

My question is, I’m I’m just getting Seagate IronWolf Pro drives, which are SATA, what cables should I get to go with this chassis/powersupply/datacable bundle?

Initially I’m starting with 6 drives, but will be expanding to 10-12 in the next 6-12 months.

Generally speaking, the backplane would have the connectors for both power and SATA/SAS. The backplane would then connect to either PCIe HBA card or to the motherboard itself.

In this post there was a picture of the HL-15 with just the backplane installed via @Glitch3dPenguin who only bought the case and backplane (as he shared in the post).

As the Z690 does not have a builtin HBA, do you have a separate PCIe card (for your HBA)?


I guess that is where I’m confused. I’ve never needed to use a HBA since I’ve always been at 6 or less drives, so I’ve always used the SATA on the motherboard without issue. I do have an LSI HBA I got a year ago for expansion but have not yet put into use. I guess what I can’t figure out is, can I not just use the SATA on the motherboard for the first 6 drives? What cable do I need for that to connect to the backplane? Looking at the picture, there is no SATA coming off the backplane, just SAS connectiors. So would this not be compatible with the motherboard SATA or should I get a different data cable?

And for the other drives down the line, (assuming I can use the SATA now) if I have an HBA with the SFF connectors on it. It looks like those may be ok with the cables shown on the pictures.

Am I close?? SFF, SAS, Mini SAS, all is where I become a little more confused coming from the consumer level hardware.

You’ll want all your data drives connected to the HBA. Do you have a model number for your HBA or pictures of it? With that we can point you in the right direction.

Yes, this is possible. I’ve seen these cables called reverse breakout cables, basically they take 4 SATA to produce a single SAS cable.

If I’m sticking to unraid (it works for me and my use) and have been using SATA ports on the motherboard for years now, I’m not sure I fully understand why I have to move to a HBA for the initial 6 drives, obviously when I expand, I’ll need to add an HBA to get more drives, but for the time being when I have the same number of drives as Motherboard SATA ports, why is a HBA required for this chassis?

Pic of the HBA I do have is attached.

Surely I can use the same hardware in this chassis? I’m missing a connection here clearly. Usually the case I use doesn’t dictate the type of drive connection, that seems odd to me.

For that select Set E or Set G when purchasing the case;

Set E
(2x) SFF 8643 → SFF 8087 [Mini-SAS-HD (Backplane) to Mini-SAS]
(2x) SFF 8643 → 4x 7-Pin SATA [Mini-SAS-HD (Backplane) to 4x 7-Pin SATA]
Set G
(4x) SFF 8643 → 4x 7-Pin SATA [Mini-SAS-HD (Backplane) to 4x 7-Pin SATA]

depending on, as others have said, the HBA you plan to use to expand to 10-12 drives. Using the SFF connectors allows four SATA channels over one cable, so it helps avoid a rats nest (one cable for every four drives instead of one cable for every drive). Luckily the backplane handles power, so you don’t have to connect up separate SATA power for every drive.

My HBA used SFF 8087, but (someone correct me if I’m wrong) I get the impression that the SFF 8643 are more current generation.

In toddler terms, since you specified Seagate IronWolf Pro SATA drives this is no different than your current server, just select the pieces that fit physically together. The challenge would come if you said you wanted to install and learn about SAS HDDs.

To help clarify, the backplane is technically a piece of hardware that is being shipped with the case. The cables are mini-sas (as listed on this page - you may need scroll to see the cables.).

The backplane is something developed by 45drives from their enterprise line. There is a hot-swap feature that is not typically available with straight cable connectors to the motherboard.

As I accepted the design by 45 Drives, I would allow them to give/share more on the technical specifics.

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An HBA isn’t “required”. It is going to be necessary in most custom builds in order to utilize all 15 drive bays, as most mobos (unlike the one 45HomeLab uses in the full build) don’t provide the equivalent of that amount of physical or logical SATA channels, but it’s not “required”.

Select “Set E” when you purchase the case and it should support your motherboard SATA connections and HBA.

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HI @HomerJSimpson, To put it simply. the backplane in the HL15 simply takes the drive connectors and puts them on a PCB board.

From there the PCB board powers 4 HDDs and connects 4 HDDs per power and data cable connector (the backplane has 4 data cable connectors and 4 power connectors) for this we will not worry about the Power.

So we have 15 Drives each connected with 4 pairs of 4 connectors, if you would like you can use set E which includes the following
Set E
(2x) SFF 8643 → SFF 8087 [Mini-SAS-HD (Backplane) to Mini-SAS]
(2x) SFF 8643 → 4x 7-Pin SATA [Mini-SAS-HD (Backplane) to 4x 7-Pin SATA]

now the SFF 8643 is the 4 connectors on the backplane itself. there’s nothing to change about that. the important part is the SFF 8087 and the 4x 7-Pin SATA.

What this set gives you is 8 SATA connections that you are already used to and then it gives you 2 other connections 8087 which would connect to your HBA for the other 8 drives.

If you wish to have the drives connect to your SATA on your motherboard this is what you would want. it allows the first 8 drives to be on the motherboard and the other 7 to go to a HBA.

If you want all drives to be connected to a HBA and not worry about having enough SATA connections or worry about the onboard SATA controller to control all the drives this is when you would want to go with a different set of cables that would match the connections on your HBA card.

Looking at the HBA card you pictured it is an i8 card meaning it will only support 8 drives. again set E will work.

if you had a different HBA with i16 you could then get everything to plug into the HBA

My recommendation would be to go with set E if you have 8 SATA connections on your motherboard and then use your HBA for the extra 7 drives on the 8087 connectors.


pretty new on building a server, i am planning to get HL15 with power supply/data cable.

can you advise on which cable set i should go with? i managed to get my hands on a supermicro X11DPL-i board, with a AOC-S3008-L8e 12Gbps HBA Disk Controller.

many thanks!

It looks to me like you need;

Set D
(2x) SFF 8643 → SFF 8643 [Mini-SAS-HD (Backplane) to Mini-SAS-HD]
(2x) SFF 8643 → 4x 7-Pin SATA [Mini-SAS-HD (Backplane) to 4x 7-Pin SATA]

The first 2x will connect to the HBA
The second 2x will connect to the mobo.

Since there are only 15 HDDs on the backplane, one of the 16 SATA channels from the backplane is unused. I assume they’ll make that one of the 7-Pin SATA connectors and mark it, but I’m not sure. Not a big deal to move cables around, or to plug in all eight 7-Pin SATA to the mobo, but you might want to be able to use that mobo SATA connector rather than having it plugged in but doing nothing if it doesn’t need to be.

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excellent! thanks for the detailed reply:)

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