Built a small machine using an Asrock N100DC-ITX motherboard, it has an Intel N100 built in and I also have 1x NVMe and 2x HDDs. The board has a DC Jack so no external PSU.

First time I booted it, the NVMe had Opensuse on it so I played around a little, no problem. When I boot into BIOS also no problem.

When I boot into Unraid, there is a strange sound coming from the back of the board, sounds like an interference sound. I cannot tell if it’s coming from the ethernet port or from the power DC Jack. I think it’s from the power.

I recorded it with my phone and bumped the sound +20 dB, this is how it sounds like. You can hear the fans and that sound. https://soundcloud.com/user-300866676-719653331/n100-1

https://soundcloud.com/user-300866676-719653331/n1002

For power I tried using both an Intel NUC 65w power adapter and an Asus laptop 90w power adapter, the one Asrock recommends on their website. The system has been running for 1-2days, with 4 containers and Home Assistant VM, it idles at around 16w. Without Home Assistant, it drops to 11w.

Any idea what that sound is?

Edit 1: If I go into BIOS and turn off Intel Turbo Boost Technology then it is silent but also kills my performance?

Edit 2 So because I did not want to leave Turbo Boost on, I did some more digging and also realized my CPU was always boosting in Unraid. using “watch grep "cpu MHz" /proc/cpuinfo” it was almost always between 2900Mhz and 3300Mhz. I installed Tip and Tweaks plugin and set Normal CPU Scaling Governor to power saver. The sound is gone and now it seems the CPU goes all the way down to 600 MHz and up to 3400MHz depending if it needs it. I don’t know if the power saver will affect performance in any way but so far so good and I don’t have hear that wheeeeee anymore.

  • Septimaeus@infosec.pubEnglish
    1·
    11 months ago

    Not sure but I’d guess VRM. Would try to localize sound with a mic to be sure. If no RMA or pending FW update, would try disabling problematic c-states and/or dampening with thermal pads.

    • OrangeCorvus@lemmy.worldOPEnglish
      1·
      11 months ago

      I tried to disable c-states and went on a lot of BIOS settings. The sounds is only gone when I turn off Intel Turbo Boost Technology. Then it’s silent but I guess it also kills my performance in Unraid now it shows it at 792 MHz.

      • Septimaeus@infosec.pubEnglish
        1·
        11 months ago

        Nice, sounds like you narrowed it down.

        You can leave turbo boost on and make more subtle adjustments using command line utilities like cpufreq or with GUI-based unraid plugins like this one.

        Before spending time fiddling with settings though, you might try using /sys/devices/system/cpu/cpu*/cpufreq/energy_performance_preference to set one of the built-in profiles like balance_power. If you do need to make manual adjustments, I would try lowering max clock speed first.

        • OrangeCorvus@lemmy.worldOPEnglish
          1·
          11 months ago

          Thanks, I changed something else, before you replied and forgot to update my reply to you, but I updated the main thread. Maybe some else will search for this exact problem so they know what to do.

          So because I did not want to leave Turbo Boost off, I did some more digging and also realized my CPU was always boosting in Unraid. using “watch grep “cpu MHz” /proc/cpuinfo” it was almost always between 2900Mhz and 3300Mhz. I installed Tips and Tweaks plugin and set Normal CPU Scaling Governor to power saver. The sound is gone and now it seems the CPU goes all the way down to 600 MHz and up to 3400MHz depending if it needs it. I don’t know if the power saver will affect performance in any way but so far so good and I don’t have hear that wheeeeee anymore.