Question regarding voltage sensor CPU 1P8 at 1.838 in B550 MSI Gaming Carbon

[Kaldor Draigo]

Do anyone knows what is this sensor monitoring?, it looks like a rather high voltage and I have no idea from where is it coming from.

I have another sensor that is showing 216ºC constantly but I mean, I know for sure that one isn't monitoring anything otherwise the whole system would be on fire.

But this one is always at 1.836v and 1.840v, in HWInfo is called VTT. 

MSI_SnapShot.bmp

[DildorTheDecent]

22 minutes ago, Kaldor Draigo said:

Do anyone knows what is this sensor monitoring?,

It's measuring PLL.

Quote

it looks like a rather high voltage and I have no idea from where is it coming from.

Normal PLL is around 1.8V. 1.9V is the generally accepted limit for most users. But it can go higher up to 2.1V (maybe more) and is useful for stabilising high BCLK.

 

It's far too high to be VTT. VTT is usually half of DRAM voltage.

[Kaldor Draigo]

12 minutes ago, DildorTheDecent said:

It's measuring PLL.

Normal PLL is around 1.8V. 1.9V is the generally accepted limit for most users. But it can go higher up to 2.1V (maybe more) and is useful for stabilising high BCLK.

 

It's far too high to be VTT. VTT is usually half of DRAM voltage.

So if it's PLL it's fine at 1.840 right?

[DildorTheDecent]

54 minutes ago, Kaldor Draigo said:

So if it's PLL it's fine at 1.840 right?

Yeah. If you really want to check to be sure then enter the BIOS and see that it says for PLL voltage.

 

Seems weird that HWINFO has given it the wrong label. I'd reinstall HWINFO to see if it corrects it.

[Kaldor Draigo]

15 minutes ago, DildorTheDecent said:

Yeah. If you really want to check to be sure then enter the BIOS and see that it says for PLL voltage.

 

Seems weird that HWINFO has given it the wrong label. I'd reinstall HWINFO to see if it corrects it.

The sensor in the motherboard says CPU 1P8, it's in the screenshot I uploaded in the OP. I could manually set PLL  at 1.8V to check I suppose. 

Edit: I don't even see PLL in the voltage options. 

Edited January 15, 2021 by Kaldor Draigo

[DildorTheDecent]

32 minutes ago, Kaldor Draigo said:

Edit: I don't even see PLL in the voltage options. 

Did you go to: OC Menu > CPU Voltages control and look for something labelled 1P8"or PLL.

 

Might need to switch from Normal to Expert mode. Tried to look in the manual as to where PLL is but it doesn't say.

 

Probably not a big deal though. But it doesn't hurt to get familiar with your BIOS.

[Kaldor Draigo]

16 minutes ago, DildorTheDecent said:

Did you go to: OC Menu > CPU Voltages control and look for something labelled 1P8"or PLL.

 

Might need to switch from Normal to Expert mode. Tried to look in the manual as to where PLL is but it doesn't say.

 

Probably not a big deal though. But it doesn't hurt to get familiar with your BIOS.

Yeah, I didn't see anything of the sort in the advanced mode. I had already looked at voltages previously when I used the new AGESA bios to undervolt with PBO and didn't see anything with that name (unless it has an alternative name). Neither is 1P8, that one only appears in the sensors when I go to the fans settings in the BIOS.