NUC fan stays on - Why?

I’m running a new NUC10i7fnh with an external USB HDD. When I turn the NUC on, its fan starts & keeps running for hours. I have the NUC on a ventilated shelf with nothing close to it, so it should be cool. Even when I’m not listening to music and the NUC is idle, the fan runs. I have to turn the NUC off to get the fan to turn off.

Even then, if the drive is powered on, the NUC restarts itself and its fan restarts instantly too. The only way I can keep the NUC turned off is to power down the 6TB library drive and then shut down the NUC.

That said, this is the first time that this drive has been attached to this NUC. Might the NUC be defragmenting the USB HDD (keeping the NUC processor active and requiring the fan)? It was my goal to leave the drive and NUC powered at all times, but not if the fan has to run constantly.


Thanks - Glenn

Is this a new Library ?
How many Tracks ?

If the drive is new , Roon will treat these files as “NEW” or “ALTERED” and import them. Its a once off process. Roon will imports the files into its database quite quickly If Roon is still importing there will be a rotating blue circle top Right

Roon then sets off to do Audio Analysis of the files. This checks audio levels in the music and drives the graphical images of sound levels on the playing area bottom screen.

This can take a while , depending on how many cores you dedicate to it and the number of tracks

I have the same NUC (the high form that allows a drive) with short of 200k tracks and its silent

Maybe try setting the number of cores to “throttled”: during the day and to MAX overnight until its finished.

If this is the case the image above will have a count showing 10000 out of 25000 etc

It also looks like the USB drive will be scanned again at each startup

For true quiet running maybe consider an internal SSD expensive but … . Mine is 4Tb , the NUC sits in front of me here and is silent

You can change fan settings in the BIOS to « Quiet » it really helps.
Reboot the NUC and press F2. You will need a keyboard and a screen.

The library is fully imported. The circle no longer chases itself at the top of the screen.

I will maybe get around to hooking up a monitor and a keyboard if the NUC doesn’t stop this. But I’m currently using the default BIOS settings.

I plan to turn on the NUC this morning and let it go all day. If it settles down by itself, all is good. Otherwise, I’ll shut it off this evening and go with the BIOS settings tomorrow.

Thanks again for the help! - Glenn

Postscriptum - I just turned on the NUC. The library drive is not powered up. The fan comes on as soon as the power button is pushed, accelerates in speed for a few seconds, slowly declines in speed, and within 30 seconds, goes off.

As soon as the library drive is powered on and initializes, I hear continuous head movement. Within a minute, the NUC fan comes back on at medium speed and the HDD stops making noise. A few minutes later, the NUC fan is still running continuously.

Factoids that may have no significance:

  • The HDD uses a USB-3 interface cable
  • The HDD is plugged into the front USB port of the NUC
  • The only other connection to the NUC is an Ethernet cable that goes to a switch
  • The switch is connected to:
    ** The cable modem*
    ** A feeder cable to the Apple TV in the living room*
    ** A MacBook Pro that I use as a business machine*
    ** A cable-based telephone modem*

I have a 5 year old 7i7 NUC running ROCK with two USB drives attached, one of which is powered by the NUC USB connection. The fan has always ran slowly, with the top of the NUC barely warm to the touch. I have never changed any of the BIOS fan settings, so it is at default.

As your NUC is new there is the possibility that it may not have sufficient thermal grease in contact with the processor/heatsink. The only way to check this is by disassembly. As the fan issue clearly bothers you, you may as well buy a suitable fanless case for it and just transfer the NUC board into that.

I have an older nuc 7i7 as well. No experience with the 10i7. It was loud even with no load on the processor. tweaking the bios settings and throttling the processor can help a lot, but was still never what I would consider to be silent like a Mac mini, which I also have. I ended up putting in a fanless case and now it’s totally silent and no need to throttle the CPU.

Well, the drive is running continuously, and is hot to the touch. The NUC fan is running continuously, but the case is cool to the touch. I’ll try hooking up a monitor & keyboard and digging around in the BIOS. If I can switch the fan to quiet mode, and let it shut down the HDD when not in use, it may be fine as is.

Start by following @Mike_O_Neill advise and post anscreenshot of your library settings?
By the look of it, your library is being analysed (the second part of library-fication). The latest version of Roon OS also did something to act more resilient to various file systems on external drives. That came with a drawback, many of us had external drives content rescanned and analyzed as Roon didn’t interpret the files as identical anymore.

The longest it’s ever taken Roon to analyze my Library has been about an hour and a half. This “drive running continuously and NUC fan running continuously” has now taken more than a full day, and the situation is still happening despite my visiting the BIOS settings.

I’ve turned off the things I wouldn’t be using such as WiFi and Bluetooth, set the fan to “quiet mode,” and disabled all the unused ports, such as the USBc on the front of the NUC.

Library settings would be available in Roon Remote? The NUC displays nothing but text saying it’s running Roon.

Yes, here, and there is more by clicking the View> buttons on the right

Issue solved. The problem WAS in the Library settings. The “Background Audio Analysis Speed” was set to “Fast (1 Core).” The “On Demand Audio Analysis Speed” was set to “Fast.” I turned both to “off,” and immediately my NUC’s fan went off.

Is there any reason to set those differently?

Thanks - Glenn

Set to Throttled , setting to Off will Prevent any new files being analyzed , Throttled will allow any new stuff to be analyzed in the background.

Depending on library size Roon will work to bring the library off disk into the memory , the NUC will whir/work during this time then should go quiet . Mine takes around 2 mins for 200k tracks along with the USB drive import

PS You still haven’t told us how big the library is -Have You ?

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That doesn’t sound like issue solved to me. It means you still have analysis in progress. It may be stuck on one track that might be corrupted or something but it was trying to do something which probably still needs to be resolved.


That’s normal , just reading the db into memory. If you go to Settings> Storage do you see any activity on the USB drive. eg mine shows the USB drive being scanned ie 2000 out of 57775 etc when I restart the NUC then it looks like this …


I don’t get that scanning notification at all. All it says is “Watching for new files in real time - 83449 tracks imported.”

Back to the analysis question - As I understand it from the information notification, the only purpose of the “on Demand Audio Analysis” is if you choose to use volume leveling. That would make sense - unless Roon knows the peak levels of each track, it can’t volume level them all. Since I don’t use volume leveling, it would seem that I’d have no need for the analysis at all?

Thanks for the feedback - Glenn

As i see it there are two processes which identify and catalog your media into the Roon Library:

  1. Identification - This where the “spinnin’ doughnut” top right in Roon notifies that the Core is identifying files that have been added, either in local storage or as favorites from streaming services.
    This part serves to identify the relases and apply metadata such as album artist, track info, covers etc. This part also builds the links in bios, reviews and in other view of Roon where metadata is linked betwen views.

  2. Analysis - This process is visible under Settings-Library and there are two processes that deal with this, the background part and the on demand part. Whichever process, it analyses the files (these are local files only, no streaming files are analysed) to provide Dynamic range classification, data for volume normalisation and for the “spectrogram” visible in the bottom part of the Roon Remote window.
    The Analysis process isn’t strictly necessary to be able to play these files so if you are uninterested in these functions i assume it is okay to disable this.

I’m sure i have missed some part so feel free to correcct me, but i think i’m in the right ballpark at least…

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Also if you disable it, and use volume levelling, Roon will perform the analysis on the fly anyway

Sounds like you’re good to go.

83k tracks is a big library may take 2-3 days (guess) to analyse

Thanks again for this information, gents. I’ve never used (and never plan to use) volume leveling, so I think I’ll just leave the analysis service off on my machine.

But I do have one additional question, please. When I got my NUC up and running with ROCK, I connected my library disc, and let ROCK index it.

I’ve noticed that ROCK has lost a fair amount of metadata that used to be there when I was running Roon on my Mac mini. Some albums have lost track names; some albums have lost cover art; some albums that were formerly listed as the same album have now been separated into multiple albums, etc.

I’m assuming I’ll have to reconstruct this data myself? I’ve forgotten how to do this in Roon, but I can research it and educate myself. Is there any “easy way” to recover this information? The backup I had of my previous Roon was located on the HDD of the Mac mini that got wiped before I sold it. And I (foolishly) failed to copy the backup before wiping that drive.

Thanks again - Glenn

If you had it set up how you liked it you should have run a back up on the old machine and restored on the new. It would have prevented a full re-analysis of your collection and hopefully have kept all the edits and manual interventions you made to make it neat and tidy.

Should have - Could have - Would have. I didn’t.

So now I’ve got to manually re-edit my library. And here I encounter a BIG problem.

The NUC with ROCK does NOT have a graphical interface (like Roon did on my Mac). So the only interface I have to Roon is on my iPad’s Roon Remote. The Roon Remote doesn’t conveniently allow such functions as combining multiple albums into one, etc.

Google says to install Roon on your Mac - but I can’t do that because I have only one authorized copy, and it’s on the NUC.

How do I get full editing capability for ROCK?