To give you some idea, aside from me going into vrm details too much.
Hardware unboxed actually made video on X570 boards tests with a 3900X.
The Msi X570 Gaming edge handled the 3900X pretty terrible,
with vrm temperatures well around the 115C.
Above the 105C is actually a number where i personally would get a bit concerned,
wanting discrete mosfets to be.
Because that is getting close to their max trashold.
Now to get a bit more into vrm detailes.
THe Msi X570 Gaming Edge is a 4+2 phase design doubled to 8+2 using IR3598 doublers.
Mosfets on the highside 2x Onsemi 4C029N’s and low side 2x 4C024N’s for each phase.
Now lets take a look at the Msi B450 Tomahawk because why not.
- 4+2 phase board controlled by a Richtek RT8894 pwm, which cannot be doubled from.
For the mosfets they use the same configuration and mosfets like the Gaming Edge.
But the Gaming Edge has twice the amount of mosfets and phases powering the Vcore vrm.
And the Msi X570 Gaming Edge was already struggling with the 3900X.
Those tests were done with just autoboost pbo enabled.
A 3800X can easally pul about 110A ish of current, the 7nm procedee,
is slightly better on efficiency and current draw then the previous gen 2700X.
Which can easally do 130A ish.
But a 3900X can easally pull 160A / 170A ish of current so keep that in mind.