high voltage on 8700k

[Yismh]

So I managed to get my new 8700k to 4.9 GHz on 1.285 Vcore, when I tried to get it to 5 GHz, it won't be stable unless I apply 1.4 volts, I have been stressing it for almost a day now, temps are 82 degrees at max and 42-45 @idle.

is that even safe for my CPU?..and why did it take that much voltage delta just to get an extra 100Mhz ?

[Crunchy Dragon]

1.4v is fine, the chip can handle up to 1.5v before it gets fried. I unfortunately cannot explain why it takes that much voltage to increase an extra 100Mhz.

[Yoola]

It's just one of those chips, you technically lost silicon lottery.

I wouldn't recommend 1.4V for everyday usage. 

And with those temps I'd go and delid that monster. 

[Jurrunio]

5 minutes ago, Yismh said:

is that even safe for my CPU?

Not quite. This voltage for Intel is only good if you can keep the temps below 70C.

 

5 minutes ago, Yismh said:

and why did it take that much voltage delta just to get an extra 100Mhz ?

You are approaching the limit of the CPU

 

4 minutes ago, Crunchy Dragon said:

1.4v is fine, the chip can handle up to 1.5v before it gets fried.

This depends on temperature. The lower the temps, the higher the safe limit of voltage.

[WoodenMarker]

31 minutes ago, Crunchy Dragon said:

I unfortunately cannot explain why it takes that much voltage to increase an extra 100Mhz.

There's an optimal operating frequency for the amount of power drawn and the efficiency follows a convex curve. CPUs are designed to be as power efficient as possible and pushing clocks higher will require even more power. Higher power consumption also leads to higher leakage and temps which also leads to even higher leakage. Better cooling can help mitigate some of this issue.

https://en.wikipedia.org/wiki/CPU_power_dissipation