TechMike’s Server Anatomy 101: SAS Backplane Cables for Dell Rack Servers


Call us gearheads, but at TechMikeNY, we’re fascinated by all of the hardware and parts of an enterprise server.  We often field questions from our customers on cable compatibility, specifically the many variables with Dell backplane cables. 

To better inform, we thought it would be helpful to describe the nuances of these backplane cables.  Call it Server Anatomy 101: Know Your Backplane Cables!

Backplane Cable Basics

Backplanes for today’s modern rack servers are almost exclusively used to house the hot-swappable drives of the machine.  (If you want to get technical, it’s a “passive backplane,” which means that circuitry to manage the communications between the slots is contained off the backplane.  You can read an excellent history of backplanes here.) 

Unlike standardized internal ports and connectors, like SATA, SAS, and PCIe, the correct backplane cable can vary significantly between the model server.  For example, (how many bays), the server generation (Dell 12th Gen vs. Dell 13th Gen), if you connect to a mini-RAID controller, a PCIe RAID controller, or the native RAID controller built into the system board, can all be factors.

This post will give some examples of the varieties of SAS backplane cables. 

TROUBLESHOOTING TIP: The SAS backplane – even if you are utilizing the native controller – must be connected.   That may sound obvious, but you would be surprised how many times a missed troubleshooting step is confirming that the SAS backplane cables are securely in place.  The server will not boot if the SAS backplane is not connected, and in the BIOS or iDRAC menu, an error, “Backplane X connector X is not connected,” will show.   


Difference Between 12th and 13th Gen Dell Rack Server Backplane Cables

The 12th and 13th generation SAS backplane connectors are different – specifically, the 12th Gen takes cable SFF-8087, and the 13th Gen (and 14th Gen) takes SFF-8643. 


Additionally, the connectors on the mini-RAID cards are exclusive to those controllers, and the connectors differ from the Dell 12th and 13th & 14th Gen servers.

One last variable with SAS Backplane cables is the consideration of how many active drive bays the server will have. Any Dell server with more than four hard drives will have two SAS backplane cables labeled “BP SAS A” and “BP SAS B.” 


One last note on split backplane cables: while any server housing over four active drives will require the second cable & connector, that additional connector is all that is needed for however many drives.  In other words, whether it’s six drives, or twenty-six drives – it will be the same split cable & connector. 

WE’RE HERE FOR YOU!  If you order a standalone RAID controller from TechMikeNY, a representative usually will reach out to confirm compatibility with the server you want to install it in.  Additionally, we’ll provide whatever cabling you need – depending on our stock – free of charge.  That’s the TechMikeNY connection!


Final Thoughts

While the nuance of cable compatibility with Dell SAS backplanes can seem daunting at first, some basic questions can you determine what cable you need:

  • What is the Generation of the Dell Server? 12th Gen takes different SAS backplane cables than 13th and 14th Gen.
  • What type of RAID controller is connected? A Mini or a PCIe? The Mini controllers have a proprietary cable that will ONLY work with that Dell controller. While the cables for a Dell PCIe card and a 3rd party card are the same, 12th Gen controllers would not be compatible with a 13th or 14th Gen Dell server.  
  • How many bays will have active drives installed? If it is over 4, you need to make sure you have the 2-connector cable. 

Lastly, it bears reminding that the integrated RAID controller in a Dell server can only configure a maximum of four drives – SATA ONLY – in RAID. 

Have more questions?  Drop us a line at info@techmikeny.com.  We do this all day and love hearing from our customers!

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