VCore extremely low

[redeyedskink]

Hi everyone,

I posted this thread on the GPU forum because I thought it might be a gpu issue, but I may have been wrong.

My computer will randomly blackscreen and restart at times. I've tested nearly everything and then found a weird issue with my voltages.

My voltages tend to fluctuate, especially my vcore. Now i know due to speedstep that a vcore should change, but my min and max value are along the lines of .14 and 1.152. .14 seems extremely low to me and was wondering if this might be a cpu issue or a psu issue.

Thanks for your help.
Specs:
I5-6600k
gtx 960
z170 gaming 5 motherboard
2x8 2200mhz ram
seasonic 550w psu

 

[Darkbreeze]

You have a manually set 1.11v vcore for what clock speed?

 

[redeyedskink]

You have a manually set 1.11v vcore for what clock speed?

Only 3.5ghz. like I said, I run everything at stock in my machine, although I could definitely overclock it higher

 

[TJ Hooker]

I've used OCCT before, it is good as a real world stress tester. But Prime95 is better, it hits the CPU harder.

Well, I'm no expert on CPU overclocking (my current rig is the only one I've overclocked, although I have overclocked it multiple times to different levels), but the way I've started doing it is:
P95 v26.6 small FFTs for thermal testing and short term stability (30-60 min)
OCCT medium data set for long term stability (overnight or whatever)

Purely anecdotal, but I've found that OCCT will catch errors faster than P95. On several occasions an OC has passed P95 for 30+ minutes only to fail OCCT in under a minute.

I have also found that there are problems with the implementation of Speed shift on Z170. Speed step seems to work fine, and it's not on every system or every BIOS version either, but if you have a BIOS version that is beyond the last version which had a microcode update, it can't easily be rolled back (The microcode changes) even if the rest of the settings can, and some can't. In some cases you simply cannot roll back beyond a certain BIOS version without a complicated and risky process involved. Anyhow, I've seen some really weird unexplained behavior to Speed shift after the BIOS changes and Windows patches in December/January of 2017/18.

Not sure that it's related, but it could be to some degree. Still going to check into this low voltage drop thing because that's a problem if it's happening to many systems.

Yeah, it's very possible my Vcore monitoring was screwed up by the latest BIOS/microcode updates. I think the timeline seems plausible with when I first vaguely remember noticing the issue.

But it must just be an issue with the sensor; there's no way Vcore is actually getting down to 10s of mV and the CPU is still able to run.

 

[TechyInAZ]

Really? I thought OCCT was worse than P95.

I might run that LOL.

I've been using P95 and RealBench for stress testing. But I stress test for at least 8 hours per run.

 

[TJ Hooker]

Haha, I'm sure everyone has their own favorite program they think works best for catching errors. Maybe if I were to run OCCT first, and then P95 (or whatever) after, it'd appear as if OCCT was letting things through that were quickly caught by the next utility 😛

 

[Darkbreeze]

Prime95, with the right configuration, is very good for catching MEMORY configuration errors. It can take a VERY long time to find a specific FFT length that causes an error though when running Small FFT. Myself, and some others that know more by far than I do, feel like Realbench is pretty much the gold standard for stability testing these days.

Stability validation procedure.

Download and install Realbench. Run Realbench and choose the Stress test option. Choose a value from the available memory (RAM) options that is equal to approximately half of your installed memory capacity. If you have 16GB, choose 8GB. If you have 8GB, choose 4GB, etc.

You can choose the full amount, but if there are other processes running in the background or one of Windows resource hogs like System restore should happen to start up while testing it could result in an error due to exceeding the available memory.

Click start and allow the stability test to run for 8 hours. Do not plan to use the system for ANYTHING else while it is running. It will run realistic AVX and handbrake workloads and if it passes 8 hours of testing it is probably about as stable as you can reasonably expect.

If you wish to check stability further you can run 12-24 hours of Prime95 Blend mode or Small FFT.

You do not need to simultaneously run HWinfo or CoreTemp while running Realbench as you should have already performed the thermal compliance test PLUS Realbench will show current CPU temperatures while it is running.

If you run the additional stability test using Prime95 Blend/Small FFT modes for 12-24 hours, you will WANT to also run HWinfo alongside it. Monitor HWinfo periodically to verify that no cores/threads are showing less than 100% usage. If it is, then that worker has errored out and the test should be stopped.

If you find there are errors on ANY of the stability tests including Realbench or Prime95, or any other stress testing utility, you need to make a change in the bios. This could be either dropping the multiplier to a lower factor or increasing the voltage while leaving the multiplier the same. If you change voltage or multiplier at ANY time, you need to start over again at the beginning and verify thermal compliance again.

A more in depth but general guide that is still intended for beginners or those who have had a small amount of experience overclocking can be found here:


*CPU overclocking guide for beginners