I have 2 NUC8i5BEH units. I'm quite happy with them except that the fans produce a high pitched whining noise that the Zoom microphone can pick up. I know that when first released the NUC8i5BEH was notorious for fan noise but I thought BIOS upgrades solved this problem. I have updated the BIOS to version 0087 which I believe is the latest. I have not changed any of the BIOS settings.
I would like to know if there is anything I can do to reduce noise.
1. Try to update BIOS again to the latest version, this time using BIOS Recovery from the Power Button Menu method. Once the update is finished, reset BIOS to default settings.
2. If after BIOS Recovery, the fan will be still noisy, disable the Intel Turbo Boost Technology, You will find this setting in BIOS Advanced > Performance > Processor.
After disabling the Turbo Boost Technology, the performance of your NUC may be slightly decreased during tasks requiring high CPU power. like gaming or video rendering (the Turbo Boost Technology automatically increases CPU frequency). However, this performance degradation will be not noticeable during normal work,like internet browsing or using Microsoft Office application. Try this and see if this helps with the noise.
Unfortunately, fan noise has been a problem ignored by Intel for years. If you search here in the forum and on other sites you will find tons of posts and users who have this problem, not only with the 8i5BEH.
Intel offers devices that are built on a very small form factor with the NUC models. In doing so, they ignore physics (performance generates heat that cannot be dissipated well).
As a customer, you have exactly two choices when you buy a NUC: You accept the noise, or you reduce the performance. However, if you reduce the performance, you could have bought a cheaper model with a "weaker" processor, where you get satisfactory noise levels without throttling the performance.
I chose an Intel NUC at the time because I wanted a small device that didn't have to be placed under or on a desk. After I got the device, I unfortunately spent too long trying to find usable solutions with BIOS updates and settings. I have not been able to do that until today. Unfortunately, I am one of those people who do not throw things quickly in the trash (although I actually think that the NUCs would be kept well there), so I keep my NUC8i5BEH now for a few years. Fortunately, there are now also some alternatives with Ry**n processors. Their form factor is a bit larger, but still easy to hide.
The really annoying thing about the NUCs is the fan's constant load changes. I have therefore also throttled the performance, but that does not make me happy.
My advice: If you can still return your NUC, then do so.
Intel NUCs cannot be quiet if they are to deliver the promised performance. If you don't need the full performance of a NUC8i5BEH, then a NUC with i3 could be a solution. The NUC8i3BEK that I know (I know two people using the NUCi3BEK) are much more tolerable in terms of fan noise. In return, they could not provide as much performance.