GPU-Z RTX 3090 (and 3080) SRC voltage (Power plane source power) readings?

[Falkentyne]

Hi, in GPU-Z, the PWR_SRC voltage is around 12.5v at idle, but this voltage rises at load --13v--14v, etc, and can go up to 15v!
Is this a bug or erroneous reading? Or is it actually 15v? There seems to be no corresponding voltage in HWinfo64, just three "Misc" voltages which are all 12.3 to 12.45v, which drop down to around 12.0-12.1v at heavy load.

What is this 15v reading and what's it doing?

 

[Elementaler]

Hello, I am having similar issue here. I am using ASUS TUF RTX 3080 OC, and the PWR_SRC voltage will reach 12.7 V max at full load in gaming. Is this a normal phenomenon?

And I was encountering random stuttering in games, specifically Monster Hunter World, the game runs well most of the time, but when it started to stutter, it will stutter throughout the remaining game session, even at low demand scene. I am running at 4k max present on this game using an AMD 3900x, so I believe this issue is not CPU related. And I saw from GPU-Z that whenever it stutters, the perfcap reason is VRel and VOp, is this anything related to the weird stuttering?

 

[Falkentyne]

Wow, 3 weeks and still no reply except one person asking about this?
I am assuming PWR_SRC is "Input Power Plane Source", but what is this voltage in HWinfo64? There are three "misc" input voltages (misc1, 2, 3) but all three are around 1.23-1.236v idle and 12.025v load, and don't seem to correspond to what GPU-Z is showing.

 

[critofur]

I have a 3080 and recently started using GPU-Z and my PWR_SRC Voltage is at 12.0 V 95% or more of the time, very rarely going to 12.1 V. Whether under "desktop use" or gaming.

Elementaler: I recommend undervolting by adjusting the voltage curve in AfterBurner - there are quite a few guides online, both discussions and YouTube videos. For my 3080, I've set it to max out at 850mV/1800Mhz, an +300 to RAM. Seems to work well, but, I hope to do further tweaking and perhaps figure out how to lower the ~36 Watts power consumption during "desktop" use such as web browsing.