Hardware noise (coil whine?) after launching application

Question

I am having strange issues with Ubuntu 20 on my laptop since the Ubuntu 20 beta.

Every time I launch an application like Firefox, Files, Store, Terminal etc. (and sometimes even less than that, such as opening a tab on Firefox) there is a "buzz" sound coming from the hardware of my laptop.

It is not coming from the speakers, headset or anything like that. No, literally from the hardware itself. Please hear this video https://streamable.com/w3bu2w (you might have to increase your volume). I have launched two apps during the video.

I do not have this problem on Ubuntu Mate, OpenSuse Tumbleweed, Windows, nor did I have it on Ubuntu 19 default flavor.

Would anyone know what the issue is?

Hardware: Acer Swift 7 (SF713-51-MG25). Graphics Mesa Intel® HD Graphics 615 (KBL GT2). CPU Intel® Core™ i5-7Y54 CPU @ 1.20GHz × 4.

Thanks.

Edit: Surprisingly, it does not cause any sound when I launch VS code or Livepatch software.

Answer 1

My dell laptop makes a similar buzzing sound, and on mine it's a known problem caused by the design of the processor (https://www.dell.com/support/article/en-us/sln84348/my-laptop-makes-a-high-pitched-buzzing-noise?lang=en). As electricity runs through it, the processor vibrates slightly, creating a sound pitched in proportion to the current processor frequency. I don't notice it while my laptop is plugged into the wall, but when I remove it from power and it goes into battery saving mode, the sound the processor makes drops into my hearing range, resulting in high-pitched buzzing.

It's possible that some new power saving feature in the beta is now bringing the operating frequency of your processor down into a range that you can hear, and if that's the case it will likely go away if you set the minimum processor usage to something higher (How to set "Performance" instead of "Powersave" as default?). Unless it seriously bothers you, I wouldn't recommend this, as it increases battery usage.

If you tried what I suggested above and it didn't work, what I'd personally do in your situation is take the bottom off, put my ear against each component, try to isolate the source and work from there towards a solution (this is how I figured it out with my dell). If you're not comfortable doing that, then I'd let sleeping dogs lie. Unless you have a hard disk drive that's tearing itself to shreds (in which case I'd think you'd have noticed a larger problem by now), it's unlikely that a little buzzing is going to cause any issues with the functionality of your laptop, even if it is a little annoying.