I have a 3570k with a Gigabyte GA-Z77x-U3H Mobo with a H100 cooler.
I reckon I have one of the worst chips for overclocking.
Ok first off, after doing hours of testing, I have come to the conclusion that my chip can reach 4.3 before it required a tonne more voltage to go to 4.4/4.5.
Using the Auto setting for Vcore on the mobo for 4.3Ghz while using Prime 95, CPU-Z reports a usage of 1.21 volts, which is the same it sets for 4.2, fair enough. However if I change to 4.4/4.5 ghz it pushes the voltage up to 1.41!! which is just ridiculous.
4.3: Max 63 Degrees Celcius
4.5: Max 80ish Degrees Celcius.
It is not hot where I live.
The strange thing is, is that people say online that if you hit about 1.4 volts that the temps should be through the roof like 90 degrees +, so why the hell does my chip need +0.2ish just to go another 100mhz but its still a lot cooler than what is recorded online? It annoys me that other people are getting 4.5 on less than what I need for 4.3.
When I go into the bios and manually set the voltage for the 4.3 Ghz overclock to 1.23 volts, the PC will not boot, whereas when I set it to auto it boots, and while using prime it only goes to 1.21 so why won't it boot with the manual voltage?
What you are encountering is the problem that the Ivy Bridge has with adding voltage at the higher overclocks.This article may help you with understanding what happens with the Ivy Bridge cpu and voltage.