I tried what you wrote saiyuki, and I think whats happening is that doing what you suggest is actually turning off AMD PB (Precision Boost), and thats why you see lower temps, cause your Ryzen CPU is not boosting anymore over your base clock (3.6GHz). You can check this yourself, as I did, using Ryzen Master (or HwMonitor, HwInfo, etc) and runing any benchmark like Cinebench or similar.
You will see that your frecuency never goes higher than 3.54GHz (more or less) =3.6 *99%
Hope it helps clarify whats happening.
Actually, with 3700X,
Idle and stresstest under Cinebench, with an old Thermalright true spirit 120M (200 watts), and thermal paste kryonaut.
Disabled PBO : idle 37/40 and stress 62/63.
Enabled PBO : idle 50 and singlecore stress 80.
Really day and night, under pbo there was always one core at 4.2ghz for no reason even on idle ...
Cinebench R20, in disabled PBO :
All CPU: 4595
Single CPU: 492
I disabled PBO but its the same. In idle aida shows my cpu is on 4275.0 MHz. I disabled PBO, and download new chipset drivers with ryzen ballanced plan but nothing work. My iddle tems are still from 40-50C. My motherboard is MSI B450 Tomahawk.
Have you tried setting the Windows Power Saving plan, if that doesn't lower your clock frecuency, then maybe, just maybe your motherboard is applying some kind of pre-factory overlock (most motherboards offer this pre-overclocking settings, I remember my old asus have it, and my new Gigabyte has it too, and this has nothing to do with PB, PBO or XFR, is a feature that motherboards offers). Best way to check this is loooking the normal view in BIOS (the non-avanced one). There should be a performance chart with some options, normal or standard is what it should be selected.
You can enable AMD COOL N QUIET on your BIOs.... Do not set it AUTO, set it to ENABLED...With this feature (only this, even with PBO ON), im getting .80 idle voltages, and 40c temp on idle...
Just check that all the options are set like the pic: https://images.anandtech.com/doci/13371/MSI%20B450%20Tomahawk%20BIOS%20%2834%29.jpg (specially the game boost in the left top corner).
Core Performance is AMD PB which is the normal speed boost for AMD CPU, that shouldnt give you many problems with temps and voltages. If you disable it, then you will see that your Ryzen only reach 3600MHz as top speed.