Question I7-8700k no longer overclocks to 5.6ghz on 1.5v.

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Nov 5, 2018
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I have had this I7-8700k at 5.6ghz on 1.5v for about 4 months now and no bsods or anything in games or benchmarks, but now I started having bsods and freezes for no reason. Is this caused by some error with windows or something?
 

Phaaze88

Reputable
Herald
I have a Cooler Master Hyper 212 evo
What kind of temps were you seeing? I'd be surprised if the cpu wasn't throttling once you put a load on it.
Was it delidded?
But anyway, since you were running it at unsafe levels of voltage, and heat as well, you've degraded the chip to the point that those clocks are no longer attainable.
5.0ghz probably isn't possible anymore, and if I'm wrong, it won't stay that way for long.

Seriously though. 5.6ghz 8700k on a 212 evo...
 
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No mention of temperatures during the 4 months of operation at those settings.
Can't see how a Hyper 212 evo would cope at 5.6GHz under load for extended periods.
If indeed you have been running at constant high temps then that can degrade your CPU and that degradation is now showing.
 
Jun 14, 2019
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The high voltage has probably degraded the cpu slightly so it's no longer capable of 5.6ghz anymore. Even if you had temps under control at that frequency it doesn't really matter because the higher the voltage the higher the delta between the micro hotspots within the cpu and the overall cpu temp.
 

CompuTronix

Judicious
Moderator
echo86,

I completely agree with Yuka and others; you're way above the degradation (electromigration) curve for 14 nanometer processors.

The only instance in which I've even briefly set Vcore to 1.420 is when determining initial overclocking capability, or perhaps to run a quick benchmark. Afterword, I immediately return Vcore to its previous level, which is always less than 1.400 for a daily driver. To be specific, this means 1.400 in Windows as shown by CPU-Z or Hardware Info ... not in BIOS ... which depending on LLC (Load Line Compensation) and / or Vcore offset, determines Vcore in Windows under 100% workload.

Yes, we know the Vcore spec in the Datasheets for the 8th Gen 14nm i7-8700K shows max is 1.52 (see page 117), but we also know the spec in the Datasheets for the 4th Gen 22nm i7-4790K shows max is 1.86 (see page 102) ... which would destroy a 22 nanometer processor in short order. There are certain items in the Datasheets that you can't take at face value, so allow common sense and experience to prevail. All is based on never exceeding 85°C under any conditions, and preferably remaining below 80°C.

There's no way an entry level budget air cooler like a 150 Watt TDP Cooler Master Hyper 212 EVO on a non-delidded 6 Core 12 Thread CPU at 1.5 Vcore isn't going to throttle under a moderate workloads like gaming, nevermind a heavy or 100% workload ... AND reach an incredible 5.6GHz ... AND remain stable without serious below-ambient cooling. NO way. Period.

An 8700K at 5.0GHz with 1.35 Vcore will consume ~170 Watts running a true 100% workload, which is P95 Small FFT's without AVX. I can only guess what an 8700K would consume under the same 100% workload at 1.5 Vcore ... AND at 5.6GHz? On a 212 EVO? NO way! Not plausible. Unbelievable and unprecedented. Something doesn't smell right. Even IF you had a 0.000001% golden chip, it wouldn't stay that way for long at 1.5 Vcore!

Excessive Vcore and Core temperature can result in accelerated "Electromigration" - https://www.google.com/?gws_rd=ssl#q=Electromigration

This prematurely erodes the traces and junctions within the processor's layers and nano-circuits, which will eventually result in blue-screen crashes that become increasingly frequent over time. As a rule, CPU's are more susceptible to Electromigration with each Die-shrink. However, the most notable exception is Intel's 14 nanometer Microarchitecture, where advances in FinFET transistor technology have improved voltage tolerance.

Here's the maximum recommended Core voltage per Microarchitecture from 14 to 65 nanometers since 2006:



Remember to keep overclocking in perspective. For example, the difference between 4.5 GHz and 4.6 Ghz is less than 2.3%, which has no noticeable impact on overall system performance. It simply isn’t worth pushing your processor beyond recommended Core voltage and Core temperature limits just to squeeze out another 100 MHz.

Beginners Guide To Overclocking Your CPU - http://www.tomshardware.com/faq/id-3761568/beginners-guide-overclocking-cpu-explicit-testing-guidelines.html

CT :sol:
 
Nov 5, 2018
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Thank you for the answers. The temperatures were ok. 40c idle and when I opened chrome for an example they jumped to about 85c for a second and dropped. In games it was around 90c and it didn't thermal throttle. The problem is fixed now because I dropped the clocks to 4.6 ghz. In avx it thermal throttled instantly so badly that I had to increase avx offset on 5.6ghz.
 
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