Product Launch: Front-Facing PCIe Slots in Select PowerEdge Servers

Dell OEM is proud to launch the Dell PowerEdge R720 and R820 with front-facing PCIe slots

As a Solutions Engineer, I have over my 12-year tenure at Dell developed a wide array of products.  My responsibilities have ranged from electrical validation and signal integrity measurements, to system level functional validation and issue investigation.  I also created a concept of a modular PERC controller which we eventually added on a PCIe Express Electro-Mechanical form factor gaining an entire portfolio of storage cards based on one suite of controllers.  This concept on modular design transferred nicely into the development of our new PowerEdge R720/ R820 with front-facing PCIe slots. 

Here is the background on the engineering development process behind our new product:

Front-Facing PCIe Development Process

Many cool projects start off several years before the product actually hits the market. In the case of front-facing PCIe, this idea started off nearly 3 years ago, with almost no preconception that I would be developing a solution that placed additional PCIe slots on the front of a server.  In fact, the entire concept started off by listening to the voice of the customer for completely different needs, and then by meeting those needs we enabled a much larger solution.

In planning for the 12th Generation PowerEdge Servers, the OEM engineering team made several design requests that would enable our OEM customers' custom solutions. By designing certain 'hooks' into the core design we could meet several OEM customization requests with simple and straight forward solutions. The main hooks were to connect power on all spare pins on the different connectors on the motherboard.  We worked with the Server Development Team to place 12V, 3.3V and 3.3Vaux power on various connectors, to allow for expansion of new devices inside the server. These power pins were actually intended for custom solutions such as adding an OS HDD inside the box, or placing a fan over a custom part that needed additional air flow. At this time, we had no concept of a front-facing PCIe Solution.

It was months later that the Dell Storage Team began driving a new concept called PCIe SSD.  This concept required a PCIe expansion bridge card to allow cabling of PCIe signals to the front of the system.  In addition, the modular storage solution created an amazing level of flexibility to the front of the chassis.  Now all the pieces were there, and the concept for front-facing PCIe slots was born but  still far from a product.  I worked with the Storage Advanced Engineers and Development Team to create a PCIe SSD solution that also enabled a general purpose PCIe expansion.  This required some minor tweaks to some of the control and reset signals.

By leveraging all of the hooks that we had been working for over a year to get in to place, the only piece that remained was the development efforts to design a cage and riser that would fit in to the front of the chassis. Even though riser development is fairly straight forward, there were still a few challenges for this project. For example:  placing a riser in the front of the chassis is an entirely new use case and the usability is not well defined. There are many subsystems that come in to play in this solution and each of these required development effort to recognize this new usage.  To start with, the BIOS has no concept of PCIe slots in the front of the system. So we had to add feature sets that would recognize this system as a front-facing PCIe product, and bifurcate the new PCIe ports as slots 8, 9 and 10. In addition, we had no definition of these additional slots in our iDRAC, and this required development effort so that we could log system events against these new slots.

Once we had support from all of the extended functions of the server, we had a solution.  But the engineering rigor does not stop there.  As part of Dell culture, all of our engineers develop a product thinking forward to the future.  In our case, the PCIe Bridge card supports Gen 2 PCIe, but our solution is going to live well in to the PCIe Gen 3 time frame. This means that we had to drive a new cabling scheme and connectors that would enable the faster speeds and feeds. This part of the development was starting to break new grounds in the industry: cabling for Gen 2 PCIe was well defined, but that solution was not adequate for PCIe Gen 3. The OEM team again worked with our Storage Organization Advanced Engineering Team to define a PCIe Gen 3 cabling solution that would eventually become the standards for the future of our PCIe SSD solution and maintained across all of Dell.


 The development of PCIe and network I/O options in front of the chassis on the Dell PowerEdge R720 and R820 Intel Xeon processor E5 family was the result of a synergy between OEM customers, OEM Engineering, and Dell Product Group Engineering. We take great pride in listening to the voice of our customers, and the front-facing PCIe solution is an excellent example of how customer request translate into a market solution.

To learn more download the spec sheets for the R720 & R820 with front-facing PCIe slots, contact us directly or reach out to your local sales team.

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About the Author: Shane Chiasson