3950x, turned off the "cpu performace boost" and got rid of the 1.5v and 90C temps and other changes...etc.
Oh, yes...Gigabyte x370 motherboard.
Ended up with the boot W10 desktop voltage being stuck at 1.0999 volts. Desktop ok, bench tests crash.
And had to use Ryzen Master to "reset", which reported "Cpu parameters reset to stock mode". (Wish I knew what that was!)
That allowed the cpu voltage to change as needed...all good now.
I finally set down and reset the Bios to defaults to find the setting that limited the voltage.
After a half dozen single changes and reboots I found that it is the cpu multiplier(40) that results in the cpu voltage sticking at 1.0999 volts.
The Ryzen Master reset results of "Cpu parameters reset to stock mode"...would love know what that change is and is it in the bios somewhere?
The "cpu reset to stock" does not have the extra cpu boosting or any other change I've been able to notice. Just that the voltages go up as needed.
EDIT... I did just notice that before I hit RM reset that the "home" listing shows 4Ghz but after I "reset" the "home" shows 4.7Ghz again.
BUT a test will only get you 4Ghz cpu max.
With CPUz HWI lists max cpu voltage at 1.296v...under 1.3 so I'm happy with that. And it idles at under 1.0volts.
I just have to run and reset Ryzen Master everytime I boot...Oh well.