A Tale of the Slow CPU – Dell OptiPlex 7050 Running on 0.79 GHz

Last week I stumbled across a good deal on Amazon for a batch of refurbished Dell OptiPlex 7050 Micro machines. The machine was from the i7 SKU, and they came with 32 GB RAM and a nice Samsung EVO NVMe SSD.

My thought was them being a great edition to my existing fleet of 7040's, that I had for years. The intended workload for these machines were strictly Hyper-V hosts, and for that the old 7040's have been absolutely great.

ConfigMgr taking forever to install…

Installing ConfigMgr on the old 7040 machines, having the same CPU as the new 7050's, same NVMe SSD, typically took about 25 minutes, but on the new 7050's it took a good hour and half. Why???

I quickly realized it was the CPU that was the bottleneck. For whatever reason it was running on 0.79 GHz instead if the usual 3.3, 3.4, or 3.5 GHz.

Task Manager showing the 0.79 GHz throttled CPU

The Research

The first thing I tried was making sure the machines had the latest BIOS update installed. That did not help, but now I was at least using that. Time to enable enhanced research mode.

After a bit of research (well, Google), I stumbled across an article at the Dell support site that claimed the 0.79 GHz CPU limit could be related to the Real Time Clock (RTC) needing a reset. So, I tried that at first, borrowing steps from the Dell OptiPlex 7050 user manual that told me to hold the power button down for 20 seconds. That did not help, still had the same issue afterward.

More research (more Google), reading about people recommending disabling Intel Speedstep and Intel Turboboost in BIOS. Tried that, did not help.

Others suggested clogged CPU heatsinks or lack of cooling paste in between the CPU and the heatsink, but no, that looked ok as well.

Finally stumbled across a comment about trying a different type of power adapter, so I borrowed one of my OptiPlex 7040 adapters, which specification-wise are the same as the OptiPlex 7050 adapters. But low and behold, after changing the adapter, the CPU started to operate in full speed.

Temporary Workaround – Using ThrottleStop

Needless to say, once figuring out it was the power adapter, I simply ordered new ones, but this time for a 7040, that I will use with the 7050. But since I wanted to get going with my lab, I temporarily used the good old CPU tweaking tool ThrottleStop, that allows you override CPU throttling in real-time. You can download the tool here: https://www.techpowerup.com/download/techpowerup-throttlestop/

By using the ThrottleStop tool I could immediately disable Turbo which unlocked the 0.79 GHz throttle and brought the CPU up to 3.4 GHz. #Shiny

ThrottleStop 9.4 in action

New Power Adapters Arriving

Today the new power adapters arrived, and just like that, super-speed is back on the machines. In the below picture the adapter to the left is one of the borked adapter, and the adapter to the right is the adapter providing the right power to the machines.

Left = Broken, Right = Working
The CPU running as expected after getting new power adapters.

Happy Deployment / Johan

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Johan Arwidmark

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Emma
Emma
4 months ago

I actually had the same issue with an older Lenovo X1 carbon, I went down the same road as you, except to find that with the x1 carbon's a battery regulator chip can cause the same issue. The only fix was to solder on a new regulator. After doing that, it fixed it for me.

Tony G.
Tony G.
4 months ago

They a lot of times don't get the OEM power brick back from the original owners when buying them and end up shipping them with knock-offs. Have had this happen many times with 2nd hand micros.

Vasistan
4 months ago

I had a same issue, but we had a support ticket with Dell and they managed with some driver. I was using other workaround also.

https://youtu.be/8qrkgtwqwtI

Steve
Steve
4 months ago

My CPU also lacks "cooling pasta" as yours did, but my CPU rubs fine in my whitebox Intel desktop. 😄

Jerry Abouelnasr
Jerry Abouelnasr
4 months ago

lack of cooling pasta in between the CPU and the heatsink 😬

Robert Collewijn
4 months ago

That's amazing, I had the exact same thing with a Dell notebook. When it ran on battery it was no problem, but when I plugged in the power it was very slow. It's took me a while to figure out what exactly was going on. good that you mention it on your website so that people can recognize and solve this problem faster.


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