This is just an observation and public service announcement. If you have the Solarflare SFC-9120 10Gb SFP+ card installed in an R740xd it will spin up the fans and be louder than it needs to be. Most likely due to iDRAC not being able to read the temperature of the card. This is common with Solarflare cards.
Here’s a screenshot of the fan speed at idle load without the card:
And here’s a shot with the card installed:
At 48% PWM the server is quite loud even with high performance fans installed.
When you’re buying a used Dell PowerEdge server or planning an upgrade, it’s easy to focus on CPU core counts and clock speeds. However, one often overlooked specification is memory speed. Even if you install high-speed DIMMs, your processor ultimately determines the maximum speed your memory will operate at.
To see how this works in the real world, I analyzed a large inventory of Dell PowerEdge 14th Generation servers. Rather than looking at the rated speed of the installed memory, I focused on the configured memory speed—the speed the operating system reports the memory is actually running.
The results were interesting.
Across the Dell 14th Generation PowerEdge servers in the dataset, 2933 MT/s was the highest configured memory speed observed.
Although several systems were equipped with 3200 MT/s DIMMs, none of the 14G platforms operated above 2933 MT/s. This aligns with Intel’s Cascade Lake Xeon Scalable processors, which officially support DDR4-2933 as their maximum memory frequency.
The following Dell 14G systems achieved the highest configured memory speed found in the dataset.
| CPU | Server Model | Installed Memory | Configured Memory Speed |
|---|---|---|---|
| Xeon Gold 6244 | PowerEdge R640 | 2 × 2933 MT/s | 2933 MT/s |
| Xeon Gold 6246R | PowerEdge R640 | 12 × 2933 MT/s | 2933 MT/s |
| Xeon Gold 6248R | PowerEdge R740xd | 12 × 3200 MT/s | 2933 MT/s |
| Xeon Gold 6226 | PowerFlex Appliance R640 S | 12 × 3200 MT/s | 2933 MT/s |
| Xeon Gold 6246 | PowerEdge R740 | 6 × 3200 MT/s | 2933 MT/s |
| Xeon Gold 6242 | PowerEdge R740 | 6 × 2933 MT/s | 2933 MT/s |
| Xeon Gold 6238R | PowerEdge R740 | 12 × 2933 MT/s | 2933 MT/s |
| Xeon Gold 6252 | PowerEdge R640 | 10 × 3200 MT/s | 2933 MT/s |
| Xeon Gold 6226R | PowerEdge R640 | 8 × 2933 MT/s | 2933 MT/s |
| Xeon Gold 6226R | PowerEdge R640 | 12 × 2933 MT/s | 2933 MT/s |
| Xeon Platinum 8260 | PowerEdge R640 | 2 × 2933 MT/s | 2933 MT/s |
| Xeon Platinum 8268 | PowerEdge R940 | 8 × 2933 MT/s | 2933 MT/s |
| Xeon Platinum 8276 | PowerEdge R740xd | 12 × 2933 MT/s | 2933 MT/s |
| Xeon Platinum 8280 | PowerEdge R640 | 16 × 2933 MT/s | 2933 MT/s |
| Xeon Platinum 8280 | PowerEdge R940 | 8 × 2933 MT/s | 2933 MT/s |
| Xeon Platinum 8280M | PowerEdge R640 | 8 × 2666 MT/s | 2933 MT/s* |
*The final entry reports memory configured at 2933 MT/s despite the inventory listing 2666 MT/s DIMMs. This may reflect mixed DIMM reporting or inventory collection inconsistencies, but it was included because the configured speed is what the operating system reported.
While 2933 MT/s grabbed the headlines, it wasn’t the most common result.
The majority of Dell PowerEdge 14G systems in the dataset were configured to run memory at 2666 MT/s. This included many popular processors such as:
These processors deliver excellent overall performance, but they don’t always operate memory at the platform’s maximum possible speed.
One trend appeared repeatedly throughout the dataset.
Several systems were populated with 3200 MT/s DIMMs, but the memory still operated at 2933 MT/s.
Examples include:
This isn’t a hardware problem—it’s exactly what you’d expect. The processor’s integrated memory controller determines the maximum supported speed, so faster DIMMs simply downclock to the CPU’s supported frequency.
Likewise, there were numerous examples where servers containing 2666 MT/s or even 2933 MT/s memory operated at only 2400 MT/s or 2133 MT/s because of the installed CPU or memory population rules.
If you’re shopping for a Dell PowerEdge 14th Generation server and memory bandwidth is important, choosing the right processor matters just as much as buying faster DIMMs.
Based on the systems analyzed:
The data reinforces an important point: memory performance isn’t determined by the DIMMs alone.
On Dell PowerEdge 14th Generation servers, the processor, memory population, and platform capabilities all work together to determine the final operating speed. If your goal is to maximize memory bandwidth, processors such as the Xeon Gold 6246R, 6248R, 6226R, 6238R, 6252, or the Xeon Platinum 8260–8280 family consistently demonstrated the ability to operate memory at the highest configured speed observed in this dataset: 2933 MT/s.
Rather than chasing the fastest memory modules available, choosing the right CPU will have the biggest impact on whether your server can take full advantage of high-speed DDR4 memory.
You may have come across a so called GPU enablement kit for the R740 and R740xd servers. In this post I’ll touch on what exactly is in the kit and whether or not you need one. Also make note of the part numbers in the title (where applicable)
What is in the kit?
The first piece of hardware in the kit that diverges from what you’d call a traditional setup is the air shroud. Dell makes what they call a GPU air shroud designed specifically for larger GPUs. The purpose of this specialty shroud is to direct more air to the GPU. In theory, it channels more air to the GPU compared to the stock shroud.
What should be in the kit but often excluded are 1U low profile heatsinks. If you order the GPU kit and have 2U heatsinks installed you’re going to immediately notice something – the shroud doesn’t fit. The original air shroud/baffle has cut outs which fit around the 2U high performance heatsinks. The GPU shroud does not. If you plan on ordering the GPU kit make sure it has the 1U heatsinks or order them separately.
If you’ve ordered an R740 or R740xd there’s a good chance you may have gotten a stripped down server equipped with riser 1 with no x16 slots, a low profile x8 riser, and a rear filler to fill up the space where riser 2 and 3 would normally occupy. The GPU kit enables your server with three x16 slots for up to 3 dual width GPUs. All 3 risers are crucial especially if you will be installing 3 GPUs in the server.
Please keep the following in mind – if you use a x16 variant of riser 1 you effectively lose the ability to use a Dell Mini Mono RAID controller. This is because all x16 risers will take up the slot required by the mini controller. You must instead use a PCIe raid controller.
There are 2 types of fans for most Dell PowerEdge servers. Standard performance and high performance. High performance fans are recommended for configurations involving GPUs, rear flex bays, NVME drives, and processors with a higher than average TDP. In this case it’s a good idea to use high performance fans with your GPU. The server will run a lot more quietly with these installed.
Lastly the kit should have the appropriate GPU power cable to go from the GPU to the motherboard.
I think the kit started out as a good idea but there are a few downsides. The first major downside is being forced to use 1U low profile heatsinks due to the design of the GPU air shroud. High TDP processors will require the 2U heatsinks to remain cool. What are you to do if you have hot processors and also a GPU? I think having to trade the 2U heatsinks for an air shroud that is arguably only slightly more air efficient for GPUs is not a good tradeoff. It makes more sense if your processors are of a lower TDP which may be the case for you. Anything below 165 Watts and you’re probably okay to use the 1U low profile heatsinks with the GPU air shroud.
The second downside is no one-size-fits-all solution. What if the included power cable doesn’t work with your gpu? What if you only need riser 3 and not the others? What if your server already has 1U low profile heatsinks?
I see these bundles and wonder who is buying them. It’s probably best to track down the part numbers you need and order what you want on an individual basis, versus the kit.
Overall I think the kit is a suggestion of parts rather than hard and fast rules for what it actually takes to “enable” your server for GPU support. I’ve built plenty of servers with GPUs and haven’t always used the GPU air shroud – and quite frankly haven’t had a single problem.
The Dell VxRail V670f is basically a PowerEdge R750 under the hood. The hardware is a carbon copy except for a handful of software and firmware related differences. If you have a V670F it’s entirely possible to rebrand to the R750 branding if you’d like. Having just performed this task it’s fresh on the mind to break down the exact process.
First you need to download the appropriate identity module.
Make sure you download the file with CustBSU in the filename. This is the customer board service utility.
Once you have it downloaded it’s necessary to extract the exe. After extraction you’ll have a .PM file extension. This is what you’ll upload in iDRAC.
This is the .PM file:
Now take that file and upload it to iDRAC under the System Update section:
Click install and enter the Job Queue when prompted.
Reboot the server and you should see the process of rebranding take place.
When finished the server will reboot once more. If all went well you’ll see the new R750 branding:
This server put up quite a fight initially. First I tried multiple identity modules before finding the correct one. Even after finding the right module I noticed that the Job would immediately fail upon upload. For each module I uploaded I had to clear the job queue and reset iDRAC before it would accept another upload without failing. If this is the case, I recommend logging into the server via SSH and use racadm to flush the queue and reset iDRAC before trying the upload again.
I came across what appears to be a rebranded Supermicro server. This is a NUTANIX NXS2U1NL06G610. Unfortunately despite many attempts and various user/pass combos I was unable to get into the BMC. This post will explain how to manually set the BMC password using Ubuntu and IPMITOOL. This is not something you can do in the BIOS like Dell or HP.
For starters get a copy of Ubuntu and make a bootable USB drive.
Once booted you can open a terminal and install IPMITOOL. The following command will update the package repositories and install the utility automatically:
My recommendation is to perform a complete factory reset of the BMC. This will ensure a clean slate. It’s possible you have a server with a non-default password. You can reset and try the defaults once more. This did not work for me but maybe it will for you.
There won’t be any output for this command but you will hear the fans spin up, indicating that the server is resetting.
Once reset you can attempt the default credentials again, otherwise proceed to set a manual password of your own.
List the user accounts on the system with the following command. You should see a user called ADMIN:
The most important column is the ID field. In my case the ADMIN account corresponds to ID field 2.
Now we can set a password of our own:
Here we instruct ipmitool to set a new password by giving it the ID of the admin user, in our case 2, and then setting the new password.
This command will tell you if it was successful or not. Sometimes there’s rules on the length and complexity of the password you can use. If you get errors just try other passwords until it lets you through.
Now you can login in to the BMC interface without problems.