i7-2700k needs more voltage than expected when overclocking

[cassini_huygens]

I'm currently trying to overclock an i7-2700k to somewhere in the mid 4 GHz range while remaining below 80°C and under 1.35V. At 4.3 GHz, the CPU crashed at 1.332-1.344V while running LinX, and the temperature was near 79°C. It may be worth noting that when LinX was running, the frequency would drop fron 4.3 GHz down to 1.6 GHz as if it was idling. I don't believe this is throttling because the throttle temperature is somewhere in the 90°C range. The CPU was stable while in-game and Prime95 blend, but not LinX.

I've seen others achieve much higher frequencies at much lower voltages than this, and I'm a little confused if there is much more I can do. Is there another voltage I should look to increase (VTT, IMC, etc.), or did I just get unlucky in the silicon lottery?

 

[hossenstein]

Sounds like a loss in the silicon lottery. Also, processors' OC ability can degrade with age, so it is possible that it isn't able at 6 years old to achieve the same performance to voltage ratio it could have when it was newer. My 4930k recently had to take a step down in clock speed for stability after 4 years of service... Hope that helps!

 

[cassini_huygens]

What do you think a solid frequency for my processor would be with as much longevity in mind?

 

[Karadjgne]

Take a look at the temps of all 4x cores individually. If you don't have sufficient cooling on the cpu and 1 core gets run at 100% with next to nothing on the other 3, by reading a single average temp of all 4 that 79°C could well be 1 core at 105°C and 3x at 50°C. Which would explain both the temps and the throttling to 1600MHz.

 

[cassini_huygens]

The hottest core (core 3 in my case) never goes over 80°C in the entire duration of the stress test.