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I have an RPC-4224 case that has 24 bays with 6 Mini SAS ports. I needed a cable to break out one of them into 4 SATA ports, so I went down to my local Fry's Electronics and bought one. The cable came with a "sideband" cable that says optional on it.

I installed it in the box and my hard drives aren't showing up in the EFI/BIOS setup. I see other cables online, specifically one from Norco (the case manufacturer) that doesn't have that "sideband" cable.

My question is, are there different types of Mini SAS to 4x SATA cables? And if so, how do I tell the difference?

Ethan Allen
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3 Answers3

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There is an excellent answer to this question in a post by barrygordon over on the unRAID Server Community:

To make it simple, if the host-controller side is a SAS connector (SFF-8470) and the target side is SATA drives then you must always use a SAS to SATA Forward Breakout Cable. If The Motherboard/host-Controller side are SATA connectors and the backplane is a SAS connector then you must always use a SAS to SATA Reverse Breakout Cable. For SATA to SATA you just use a "SATA" cable as there is only one type, although they do come in different lengths. For SAS to SAS connections there is also just a single cable type.

See also this excellent answer to How exactly does a SAS SFF-8087 breakout cable work? + RAID/connection questions.

Also, as Alex, said in comments:

Some confusion appears to stem from the fact that backplanes exist that have individual SAS/SATA ports such as the SuperMicro SAS743TQ. In this case, you do need to use forward breakout (e.g. 1x 8087 -> 4x SATA/SAS) - despite the fact that you are connecting those forward facing cables to the backplane.

So, to summarise:

Cable needed           SATA drives/backplane  SAS backplane
---------------------  ---------------------  ----------------
SAS host/motherboard   Forward breakout       Mini SAS cable
SATA host/motherboard  SATA cables            Reverse breakout
Mark Booth
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  • Some confusion appears to stem from the fact that backplanes exist that have individual SAS/SATA ports such as the SuperMicro `SAS743TQ`. In this case, you do need to use forward breakout (e.g. 1x 8087 -> 4x SATA/SAS) - despite the fact that you are connecting those forward facing cables to the backplane. – Alex Oct 05 '21 at 05:49
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    Thanks @Alex, I've updated my answer to make this more clear. – Mark Booth Oct 06 '21 at 11:21
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There are multiple types of SAS connectors. Generally mini-SAS will be SFF-8086 or SFF-8087; according the the product page your case uses 8087.

Andrew
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Actually using the wrong cable prevents controller from detecting drive. In the case of SFF 8470 cable it is easy to convert a host type into the other one and the other way round, I did it and it works, looking to the pin layout you can understand why it works. Just un-screw the connector of the SFF8470 cable, flip over the cable inside (to swap transmitter and receiver pins), box it up again, plug it in, that's all.

giorgio
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