__blackha7__,
As you've been a Member since November 8th, 2016 but have 35 posts, we unfortunately don't see you here very often, so it's always interesting to correspond with someone of your caliber. Perhaps we can yet provide you with some acceptable insights and perspectives regarding your queries.
As you may know, Intel's Datasheets for the 22 nanometer i7-4790K state the maximum Core voltage is 1.86.
See page 102,
Section 7.8,
Table 48,
top row,
5th column -
Desktop 4th Generation Intel® Core™ Processor Family, Datasheet, Volume 1. Regardless, since in reality we know the processor would quickly fail at that Vcore, the maximum practical Vcore is far lower.
A value of 1.360 is supported by
Silicon Lottery, which is a company that tests, bins and sells professionally delidded and overclocked "K" CPUs. However, for longevity we instead recommend a maximum Vcore of 1.300. Refer to the
Devil's Canyon table in
Historical Binning Statistics.
Similarly, as my esteemed colleague,
Darkbreeze, has pointed out, Intel's Datasheets for your 14 nanometer i7-9700K state the maximum Core voltage is 1.52.
See page 117,
Section 7.2.1.1,
Table 7-2,
top row,
6th column -
8th and 9th Generation Intel® Core™ Processor Families Datasheet, Volume 1. Regardless, since in reality we know the processor may quickly degrade at that Vcore, the maximum practical Vcore is considerably lower.
A value of 1.450 is supported by
Silicon Lottery, but again for longevity, we instead recommend a maximum Vcore of 1.400. Refer to the
Coffee Lake table in
Historical Binning Statistics.
As
Darkbreeze has also pointed out, at 1.390 Vcore, you're within the safe range for long term use.
Just for the benefit of less informed users, if common sense prevails, then one-size-Vcore-fits-all is a serious misconception. Here's the maximum
recommended Core voltage per Microarchitecture from 14 to 65 nanometers since 2006:
Although these recommendations may seem a bit on the conservative side to certain users, out of respect for the hard earned parts and property of others, and the work many invest in their rigs, we do not condone higher Core voltages. Core temperatures, electromigration and degradation curves aside, these recommendations reflect the consensus typical among well informed and highly experienced system builders, reviewers and overclockers.
We hope this helps to ease your mind.
CT