Hey gang,
Got a strange one going on here.
 
So a few weeks ago I noticed my system getting a little unstable, so I upped vcore from 1.22 to 1.24v.
That stabilized things nicely. Plus it used to get stuck every now and then on post code 97, and that even too care of that issue also.
This morning, it stopped on 97 again. So I went into bios and took a look, and saw my voltage setting had changed from Adaptive to Override. Bear in mind I had not been in the bios since upping vcore  to 1.24 a few weeks ago, and it was set to Adaptive. Kind of odd.
 
So I changed it back to Adaptive, and did a run of Intl Extreme Utility stress test ( 20 min ). I noticed my core temps were getting much higher than they used to while doing this - rather than low to mid 70's, they were getting into mid to upper 80's.
Took a look at voltage whilst running with CPUID, and it was really getting up there under load like around 1.4v. Previously it would only get up to like 1.36v very occasionally whilst stressing. So it is not the cooler ( Corsair H150i Pro), rather it is the extra voltage now being applied.
 
I have been lowering vcore, and now have it all way back down to 1.20v. However, it is still bumping up to like 1.38v under load during stress testing with temps in low to mid 80's. Previously it would not have even run at 1.20v with my OC settings. Now my idel temps are certainly better, like 29c versus around 32c before.
Running 5.1 GHz on all 8 cores, no HT. Adaptive Vcore. Vdroop at -25%.
I did a power flush of the system and ran again, no difference.
 
Anyone have any clue why suddenly my Z390 Dark is throwing more voltage into the CPU ? Or am I losing my mind? Lol.
 
 

This has got to be about the strangest thing I have seen in all my years of building my PC's.
So earlier today, I loaded bios defaults and re-flashed the bios just in case mine had somehow got corrupted.
No difference.
 
So I went about lowering my target voltage first and stress testing in between, then increasing the vdroop.
I have now got the system about where it was core temp wise while stress testing to what it was previously.
However, my new target voltage in the bios is 1.05v. And my new vdroop setting is +75%.
My core temps while stress testing are mainly in mid to upper 60's with peaks in low 70's. About what they were previously. Viewing the voltage in CPU-Z, it bops around 1.32-1.36v whilst stressing. About where it was previously.
 
So just a couple of days ago, I had to run 1.24 target voltage in bios and had a vdroop of -25%, and it was stable and temps about as above.
Now, for some unknown reason, I have had to do the following to get about where I was:
Target voltage - from 1.24v - 1.05v.
Vdroop - from -25% to +75%.
 
Leaving it at my previous setting I was running, core temps all of a sudden were up much higher, likely due to higher voltage being suddenly applied.
 
Very strange, and one I will probably never understand...
Will be interesting to see what tomorrow brings. 
 
 
 

Wow. Very strange.

Sajin
Wow. Very strange.

Yeah I hope it is not a harbinger of something about to give...

@d.burnette,
 
I have no input regarding your issue.
 
I just wanted to say that running stress tests at 5.1 and 1.05V; WOW! That is a really good CPU.
 
I personally do not use XTU, preferring LinX, AIDA64, P95, RealBench for stress testing, but I cannot get anywhere near 5.1 and 1.05V.

kelkel1
@d.burnette,
 
I have no input regarding your issue.
 
I just wanted to say that running stress tests at 5.1 and 1.05V; WOW! That is a really good CPU.
 
I personally do not use XTU, preferring LinX, AIDA64, P95, RealBench for stress testing, but I cannot get anywhere near 5.1 and 1.05V.

Well I wish I could say oh yeah baby, but actually I am quite uncomfortable with it - as up until just a few days ago it required 1.24v to be stable. Anything less and it was not.  Then suddenly I notice my core temps had gone way up for no reason, and saw my vcore under load while stressing was higher than usual explaining the higher core temps.
 
The above is what I adjusted to - 1.05v with +75% Vdroop, to get it back to where I was originally with 1.24v in stability and core temps. As I was adjusting voltage down and stressing I was quite surprised it was remaining stable. Almost like the voltage setting in bios is off now or something. I sure can not explain it.
I will certainly be keeping a close eye on it over the next several days. But for now it is running great and my core temps are back where they were previously.
 
I am really not sure I am in fact running a lower voltage than I was, just having to run a lower vcore setting to get the same voltage if that makes any sense. Very weird. Like there is a difference in what the vcore is set to and the actual voltage being applied now.

Perhaps the Internal VR AC/DC Loadline values got changed?
Does the Dark have access to AC/DC Loadline?
 
Intel max spec is 1.6 mOhms for AC and DC Loadlines.  Higher AC Loadline will cause higher vcore at load. (DC Loadline is used for power measurements only).
AC/DC Loadlines set to 0.01 mOhms (no resistance) will require a higher target adaptive voltage (Significantly) than AC/DC at 1.6 mOhms.

Is your OS set to performance?   sometimes OS updates (sometimes automatic) can put it back to balanced.   Thought I read that somewhere.  May contribute why your stabile settings had to be changed.   

Delirious
Is your OS set to performance?   sometimes OS updates (sometimes automatic) can put it back to balanced.   Thought I read that somewhere.  May contribute why your stabile settings had to be changed.   

Yes it is set to performance.
Thanks,