Question Periodic CPU Overvoltage error in post - Need some help


Platinum Member
Aug 7, 2003
System is a 5950x in a Crosshair VIII Dark Hero. PSU is a Corsair AX1600i.

I'm o/cing with both PBO and manual o/c due to Dark Hero dynamic feature. CPU is oced @4.5GHz all core with 1.3V both in vid and vcore set.

While system works flawlessly all the time, no throttling issues, stable and tested with P95 and thermals are always normal w/o issues, sometimes in post I get the overvoltage protection error press F1 to enter bios. Now in bios I might get crazy value when this happens like 1.9V but gradually this value falls if I let it.. Most of the times I don't even need to close psu and open it again I just save and exit w/o changing anything (because the vcore value starts to fall in the mobo sensor). I want to note here that I haven't turned off the OVP/OCP protection in bios and of course I will never do it.. I don't even ignore the mobo sensor in the case of being faulty.

This happens one in 20 posts or something. Most of the times the values are like these in HWINFO as you can see in the attachment, but when the message appears the vcore value of the mobo sensor on the right might show the crazy 1.8-1.9V value. Which as I said gradually starts to fall by itself. Sometimes the vcore sensor does not even show up in hwinfo! The SVI2 TFN always does though and is always consistent in measurements. Only the mobo sensor shows inconsistencies or disappears completely!

I reverted back to the previous bios revision just to check because the latest for Dark Hero is a beta one. It doesn't seem to help.

So what do you think might be the issue? Should I worry about PSU or mobo giving bad power or it might be just a faulty sensor?
What would you recommend me check just to be on the safe side?

Thanks in advance for any help!


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Apr 27, 2000
It's hard to diagnose since you're using a feature exclusive to the Dark Hero VIII. There's no telling what bugs/unintended behaviors exist in dynamic OC mode. 1.9v is really high, even for low-current operation. The boost algorithm shouldn't be choosing voltages higher than 1.5v or so under any circumstance. Typically spikes that high could only be possible while using extreme LLC settings.


Senior member
Sep 4, 2016
I saw some posts reporting the same issue. First thing to try and troubleshoot is to load UEFI default settings, use the PC for a while and check if you still see this behavior.
It's probably a firmware bug or sensor fault as 1.8V/1.9V would fry the CPU if true. Also try some different UEFI versions, maybe older and newer as you don't know where a bug might have been introduced.
Last option is to contact Asus and maybe try a RMA.


Platinum Member
Aug 7, 2003
Thanks I load default fail safe settings in bios and the issue seems that is resolved at least for now.. It's probably a bug, there's no way humanly possible that 1.9-2V would have been introduced in vcore and I'd have a perfectly functional cpu with normal performance/thermals, that is if it had managed to survive such voltage even instantly. Mobo wouldn't allow such voltage also I haven't disabled and would never do of course OVP..
Will closely monitor it though.