So I have a 9900k and the ASRock phantom gaming it/ac z390 and I've been overclocking with this board for a couple of months. I updated hwinfo a couple of weeks ago to the latest version and they have a sensor called "VR VCC Temperature (SVID)." Supposedly this is the VRM temperature for the motherboard. Running stock CPU speeds and Prime95 small fft with avx I can get the VR VCC Temperature (SVID) temp to hit 110F. While overclocking, i can get it to thermally throttle at around 125F.
I have read a lot of reviews stating that the VRM is great on this motherboard, but I am running into problems with temps. I have not taken the VRM heatsink off to inspect if the thermal pads are making good contact, but I may do that if other people report that this temperature is out of the ordinary. I understand that Prime95 small fft with AVX is the worst case benchmark, but I have pretty good airflow in my case (a 120mm and 140mm in the top left corner right by the VRM).
Also, maybe this hwinfo sensor is not reliable or calibrated properly for my motherboard? Even if that is the case, I can still get it to thermal throttle when I have 1.33v at the highest LLC (the cpu drops to 3600mhz, but temps are still in check).