Risers, PCIe Cards, and Brackets. The Basics and Pitfalls if You Are A – TechMikeNY


Risers, PCIe Cards, and Brackets. The Basics and Pitfalls if You Are Adding Components to Your Dell Server


At TechMikeNY, we work a lot with the architecture of the Enterprise servers that we refurbish and resell.  Since we field so many questions with customers wanting to expand the capability of their server through PCIe cards, we thought it would be helpful to give a summary of Risers.  We’ll also share some caveats and pitfalls you may run into should you ever decide to upgrade your Dell server.  (SPOILER ALERT – prepare for unforeseen variables with PCIe brackets when adding a second processor to certain Dell servers!)

Risers.  The Basics.


A Riser is simply an expansion that connects to the server’s system board for the sole purpose of adding PCIe cards (RAID controllers, network cards, and graphics cards are common types of PCIe cards).  Risers are exclusively for PCIe cards and the different sizes and configurations they come in (more on that below). 

Here are two brief, key principles on Dell Risers:

  • Risers are not interchangeable between Dell server models. For example, a Riser for an R640 server could not be installed into an R740.
  • Dell servers must have the Risers installed, even if you are not utilizing any PCIe cards on that Riser. While technically the server will boot and run, you will be pestered ceaseless with a “riser interconnect failure” error message.  (HPE servers have more flexibility with removing Risers.)

TECHMIKE SHARES HIS INSIDE KNOWLEDGE.  While Risers are not cross-compatible between Dell server models, we’ve discovered some nuances with this rule.  For example, Riser 1 on an R720XD will work in the R730XD Riser 1 slot – but not the other way around.  If you know of more Riser exceptions, let us know!  We love collecting knowledge from our customers and fellow experts!

And Then Things Get Complicated….


  • The number of Risers can depend on the chassis – even if it is the same server model. For example, an R620 8-bay could have a different Riser configuration and capability than an R620 4-bay server. 
  • Some Dell servers will ONLY utilize/activate the Riser 2 or 3 if a second processor is installed. For example, an 8-bay R620 will only have the additional Riser active if the second processor is installed.  

So How Can You Know Which Riser is Controlled by Which Processor?

One sure-fire way is to take a look at the Riser installed in the server.  If you see “CPU2” on the Riser, that means that Riser will only be usable if that server has a second processor installed. 

Keep An Eye on the Brackets!

While Dell servers can take Half Height and Full Height and Half Width and Full Width PCIe cards, adding or moving PCIe cards within a server can cause a compatibility pitfall.  Specifically, a properly installed PCIe card’s bracket longer fits or aligns with the ports on the server after being moved to another Riser.  Insanity! 

For example, moving a PCIe NIC card from Riser 1 to Riser 2 – or even adding cards to Riser 2 could cause the network ports of the bracket to misalign – even though the card is installed perfectly into its Riser. Our Techs have run into this complicated scenario, so we share it as a heads-up: Be careful when adding or moving PCIe cards to Risers and may need to reconfigure or procure different brackets.  

Final Thoughts

The variables and complexity that you can run into when installing PCIe cards into Dell servers can seem daunting at first.  Fortunately, at TechMikeNY, we work with these servers all day and have seen it all. 

So why not use us as a valuable resource?  Never hesitate to email us at info@techmikeny.com.  We love hearing from our readers and answering their questions!  Really!


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