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[SOLVED] Vcore is swinging wildly, CPU no longer behaves like it did!

Tags:
  • Overclocking
  • Cooler Master
  • CPUs
October 10, 2014 12:19:38 AM

My system,

CPU: i5-3570k
Mobo: Gigabyte ga-z77x-ud3h
Cooler: Cooler Master hyper 212 evo

Started OC'ing last night and everything was going really well. Decided to OC by changing both the CPU multiplier and the turbo multiplier.
Took the cpu multi to 42 and the Turbos to 46, 46, 45 and 44.
Seemed stable at around 1.19v fixed. Checked with 10 minutes in Prime and standard run in IBT.
Other BIOS adjustments include:
Turbo Power Limit and Core Current Limit: 250
C1E: enabled
C3/C6: enabled
EIST: enabled
LLC: Turbo (lvl 2)

This resulted in:
Vcore (idle): 1.176
Vcore (IBT standard): 1.188
Temps (idle): <=36
Temps (IBT load): <=78

Now with success under my belt I wanted to switch over to using offset voltage, but ran out of time and had to leave that for today - and that's when things started to go wrong.
After determining my VID by loading the optimized settings, turning off all C-states and recording my VCore I came to the number of 0.075 (1.19-1.115=0.075) which I entered in as my DVID. This however led to me reaching a temperature of 84 (the highest temperature I had reachED so far and maintained for no more than a few minutes) in prime and a voltage under load 1.272; clearly something wasn't right.
Since then I've been tinkering trying to figure out what my DVID should be. So far I've tried: -0.05, -0.0015, 0.005, 0.015, 0.02, 0.05 and 0.075. The 0.05 and 0.075 both led to temperatures and voltages that were too high (the voltages seemed to fluctuate quite a lot too), while 0.02 and 0.015 caused my machine to run fine in prime and IBT but freeze whenever I loaded my BIOS (weird right?). The numbers lower than that caused my machine to just freeze when powering up.
By this time I was starting to get annoyed and tried going back to my 1.9v fixed settings but noticed that with the onset of daylight my ambient temperatures had risen and I was no longer getting 78 in IBT but rather 80. Also I got a random BSOD and chrome crashed a few times. I decided it was time to pack it in with an OC of 4.6 and go back to 4.5 (I decremented all multipliers by 1). This too was now too high and I lowered it again to 4.4 (again decrementing all multipliers by 1).
This final adjustment is why I'm here now.
Going back to my desktop I noticed that my Vcore was swinging wildly between 0.9 and 1.3 but decided to run IBT anyway - this decision nearly caused me to poo myself as I watched my temperatures rocket up to 91 degrees. I quickly terminated the test and loaded up optimized settings in my bios. Returning to cpu-z and IBT I saw that my VCore was still fluctuating heavily between 0.75 and 1.116 but my temperatures were back to there pre-OC safety (as determined by another IBT run). Again I changed my settings back to 4.4 (assuming I must have changed something I shouldn't have by mistake) but again my temps and volts were straining towards destruction. Now I'm scared to do much of anything without some guidance. I tried hard setting my volts to 1.115 (their auto value) but unfortunately my VCore is an unstable as ever.

So, what is going on? Have I somehow damaged my CPU? And if so, how could I have done that without ever going above a cpu-z reading of 1.37v, or a realtemp reading of 85.

If there is any additional information you need please ask; I've written most of my adjustments down in case of just such an occurrence but I am currently at a complete loss as to what to do.

Thank you for your time.

EDIT: Just noticed something else, whenever I go back into my BIOS I find that my CPU vcore has been reset to auto.
EDIT2: I haven't been able to replicate my first EDIT, whatever I set seems to stick now. Assuming that was somehow user error I'm still left with the following problem: The auto setting allows the VCore to change more than what I would think is normal and certainly more than it used to. This isn't game breaking as I can always just use a fixed voltage, still it would be nice to have that option back. The only thing I can think of now is that it's original setting was not auto and that loading optimized defaults is not returning it to the state that I bought it in.
FINALEDIT: Alright, I think this is how it breaks down. For some reason my cpu voltage would occasionally not stick to what I set it to and default to auto. The only explanation I can think of is user error, though it galls me to say that given the frequency of the occurrence. Either way I can now say with confidence now that when I change the cpu voltage to fixed my voltages in cpu-z remain steady. Using this I discerned my stable settings for a fixed voltage OC (cpu 4.1; turbo 4.5, 4.5, 4.4 & 4.3; all c-states enabled except C3/C6 [which crashed my system due to low voltages], LLC at lvl 2, and cpu voltage at 1.130). Then in a fit of determination I tried yet again to discover my VID, this time managing to hunt down a version of core temp (RC7) that hasn't been released yet. This revealed my actual VID which was 1.1959 (miles away from the other method I used). Using this I calculated an offset of -0.065 which in turn has, to my apprehensive astonishment, fixed my problem. My voltages remain stable now, no wild variations, just small jumps between 1.116 and 1.128 and it seems *crosses fingers* that I have a stable OC. During my searching around online I found a forum post where some other unfortunate soul had been having the same difficulty with the exact same processor and mobo combination - his solution was to simply use fixed voltage - but it seems that with just the right settings the voltage can be stabilized and an offset voltage used. The only question remaining is why my vcore was more mobile after loading optimized defaults than it was when I started this adventure. Either way, I have added the word solved to the title of this post; maybe it can help someone else.

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