Hello,
 
I recently obtained an 8700k from Silicon Lottery that was binned for 5.1 GHz at 1.41v.  I am entirely unable to obtain stability on my computer at 5.1 GHz (it will boot but crashes during benchmarks and within minutes of starting a Prime95 26.6 Small FFT run).  While trying to get to 5.1 GHz stable, I locked the ring bus at 43, ran 2 sticks of corsair 8 GB 3600 mhz ram at 2166 mhz, and tried both the "override" and "adaptive" settings for the core voltage.  The chip remains unstable even if I up the vcore to 1.43v.  I contacted Silicon Lottery about the issue, and they gave me the following information:
 

Looking at our notes for your processor here during testing, it went through 4 hours of non-AVX Prime95 small FFTs at 5.1GHz/1.38V, and the peak core temperature was 86C during that test (Corsair H100i, Maximus X Hero, 3200MHz DDR4).
 
If memory is being run at 2133 the only thing deviating from our QVL is the motherboard. Unfortunately I don't really have any other advice I can think of. If you'd like we can start a warranty exchange to get it sent back here and tested again to confirm. If it still passes our tests here though, there isn't much that can be done as any replacements would probably show the same result with your setup.

 
Is there something different with the EVGA boards that would result in them overclocking differently or worse than an ASUS Maximus Hero X?  Am I missing something with BIOS settings on this board I should try?  Any help would be appreciated.
 

Thanks for the reply. That you can run your chip at 5.0Ghz using only 1.2v adaptive is, to me, a sign you have a pretty impressive chip.  I imagine if I could run my chip stably at such a low voltage my temps would also be very comfortable, and I probably would have no issues upping the chip's multiplier to at least 5.1.  However, I can't do that.   I can run mine at 5.0GHz very stably at 1.35v adaptive with an avx offset of 0 if I don't use prime95 avx to test and of 1 if I do--temp throttling causes issues for me at avx of 0 on 5.0 GHz. I can also very stably run my RAM at 3866 Mhz 17-17-17-36 at 5.0 GHz (still playing with this part to see if I can do better).  I just can't get the chip to hit the 5.1GHz that it is apparently supposed to be able to hit without going insanely high on the voltage and similarly running into throttling issues.  If I'm not missing any secrets with the BIOS settings, maybe I just need to send the chip back for a warranty replacement.

Have you tried leaving the Ring Ratio setting in the BIOS on "Auto" instead of setting it to 43?