New machine, strange interference sounds when Unraid is up and running.

[chcrw]

I am building a new PC with an Asrock N100DC-ITX, it's a motherboard that has a DC Jack so no external PSU. I plan to use it with 1x NVME and 2x HDDs. 
At the moment, the HDDs and the 19V 90W AC Adpter are being delivered but I wanted to play with Unraid to get familiar with it.

So I tested the machine with a 1TB WD SN570 NVMe and 1TB 860 EVO SSD. I have an Intel NUC so I used its 19V 65W power adapter.

 

Initially on the NVMe, I had Opensuse so I played around with it, no problem. When I booted Unraid, the moment I could access it, I kept hearing some strange interference sounds coming from the DC Jack. Really weird. The sound was not present while Opensuse was running nor is it present in BIOS. Only when Unraid is running. There is also no such sound when the Adapter is used on the Intel Nuc.

 

Here is a sample I recorded with my phone, I bumped the dB +30 so you can hear it. What can it be and why? 

[mike175de]

Same here with my new build on N100DC-ITX.

 

I contacted the Asrock support. As soon as I get a reply, I will post it here.

 

Greets Michael

[chcrw]

1 hour ago, mike175de said:

Same here with my new build on N100DC-ITX.

 

I contacted the Asrock support. As soon as I get a reply, I will post it here.

 

Greets Michael

Hey Michael,

 

I actually solved it but I never came back here to update it. It's been super annoying but I managed to figure it out myself.

 

The sound goes away if in BIOS you turn off Intel Turbo Boost but that limits your CPU so you don't want to do that. But that's how I figured it out what it was.

 

If in Unraid you open the Terminal and type the following command, you will see that your cores are almost always at around 2800-3200 MHz, they don't really go down.

watch grep \"cpu MHz\" /proc/cpuinfo

 

To fix it, I installed the Tips and Tweaks plugin from the apps tab. Then, in the Settings tab go to Tips and Tweaks, scroll down to "Normal CPU Scaling Governor" and set it to Power Save. Then it should be silence :).

Edit: Ok I listened to my PC again and it doesn't go away 100% but it goes from constantly making noises to every 2-3 seconds, I guess when the CPU goes into a higher MHz. If you disable "Enable Intel Turbo/AMD Performance Boost?" in Tips and Tweaks it's 100% silent but then the CPU is limited to 800MHz.

Edited December 20, 2023 by chcrw

[mike175de]

Thx chcrw for your reply.

 

I will try your solution.

 

BTW I received an answer from the Asrock-Support:

 

Quote

 

Sometimes this is coil whining, but there are no coils near the DC jack.

Maybe the powersupply is causing this, we sometimes see this, with other Mini Pc's, where under load, the adapter itself is making this high pitched noise.

But I honestly wouldn't know, how to solve this, besides returning the board to the seller, and het an exchange.

 

 

I replied that this isn't a problem with my special mb, that I tried already two differnent powersupplies and even bought another n100-board with the same issue - instead it seems to be an issue of all the boards.

 

Greets

[chcrw]

4 hours ago, mike175de said:

Thx chcrw for your reply.

 

I will try your solution.

 

BTW I received an answer from the Asrock-Support:

 

 

I replied that this isn't a problem with my special mb, that I tried already two differnent powersupplies and even bought another n100-board with the same issue - instead it seems to be an issue of all the boards.

 

Greets

So it seems it's a general problem. I also wanted to maybe buy a second one to test if it's the same sound. I also tested with 2 separate power adapters, one from an Intel NUC 65W and the one I'm using an Asus 90W I got from ebay, it's the one they recommend on the Asrock support site. The problem is with the board, don't know if they could do something via a BIOS update. My solution really brings down the sound, it's only now and then and a lot quieter.

[mike175de]

Got another reply from the Asrock support:

Quote

 

Hello,

 

I don't think there is a BIOS fix for it, but in BIOS>> Advanced>> CPU Configuration,. You can play around with the C state settings, to find a solution.

 

Kind regards

 

 

Seems that they don't care about that issue.

 

Greets

[ppn7]

Has anyone tried with a 12V power supply? It seems that this is compatible from what I read on another post. Maybe this can reduce coil whine?

[phillo92]

I just installed Unraid on my motherboard and I have the same problem.  

I ordered another power supply, thinking that the noise might be coming from there, but I have the feeling that it won't do any good.

[trurl]

Do you have the same motherboard?

[phillo92]

35 minutes ago, trurl said:

Do you have the same motherboard?

Yes the Asrock N100DC-ITX.

With the Tips and Tweaks, by changing "Normal CPU Scaling Governor" to Power Save, the noise is lower.

Edited February 8 by phillo92