After 3 days of investigation I found out when Primary sensor selected as 'Procesor' regulation does not work well.
Super Quiet mode - how to:
1. Go to Bios and select Quiet, Procesor and Motherboard sensors.
2. Save and reboot (it will save hidden parameters: max duty cycle =66%=3340rpm ; trigger temperature=~95C)
3. Go to bios and change to PCH and sliders acording picture (you can go also 65C and 22%)
4. Save and reboot
With PCH it is monitoring cpu temperature. What is "Procesor" then? - Intel, we need a fix!
Lower Turbo boost time window to 32 sec in BIOS. Leave power on default 30W/50W for NUC 8i5.
And done. Reboot. Run some stress test.
Check for cpu temp vs fan rpm in hwinfo64.
It is intended for normal businness work (not gaming, not for running simulation or long time high utilization). Cpu gets little hotter, but should not cross 92C under heavy load.
If you like this Super Quiet settings, leave some comments.
Yeah, and took me hundreads of reboots. :)
On your own risk.
As I understand they interpolate this discrete points https://github.com/pop-os/system76-power/blob/7a43106205b63d159b2c17ef848f3f9abbcaed19/src/fan.rs#L1... Anyway it's just an example.
Let me summarize what is going on here...
Analysis showed that there was a bug in the EC firmware that caused CPU (package) and PCH temperatures to be swapped. This bug was fixed and the updated EC firmware was delivered as part of the BIOS 78 package. Now, the EC firmware, like the ME firmware, once upgraded, cannot be downgraded. If you upgraded to BIOS 78 and then downgraded to BIOS 77, the EC firmware with the fix is still going to be installed and running. For those that implemented custom configurations based upon how the EC was (incorrectly) handling CPU and PCH temperatures previously, you will need to modify your configuration to work with the new firmware.
Make sure you load F9 Defaults after a NEW BIOS update. Settings do not automatically get changed after you flash to the new version. Could be some of your settings are leftover from the previous BIOS.
I want an always-on silent box. This is what I have done with satisfaction in the BIOS settings:
- Turbo boost disabled (but I suspect this is not significant)
- Low power mode
- fan off at 45°C (but this is ignored, in fact the fan never stops)
CPU temperature: min 40°C, speed min 1%, increment 2%/°C
Memory temper.: min 35°C, speed min 1%, increment 3%/°C
On an idle box at ambient temperature 21°C I read a core temperature around 42°C