Foxrage2 :
I have my CPU OC'd to 4.0 ghz and I was wondering what a good vcore voltage setting for this would be.
You should be able to run 4.0ghz in the 1.20v range some of these suggestions at 1.32 are very high for 4.0ghz I run 4.5ghz at 1.325v Fixed Voltage, I'm not saying all 2500Ks run the same but they are very similar and the way you use your voltage settings, meaning fixed or offset, and additionally load line calibration settings affect what you can do regarding certain multiplier levels.
I would suggest reading and studying some type of overclocking guide for your own knowledge, because 4.0ghz can be done with a 2500K, (literally with it's hands tied behind it's back, if it had hands.)
Some of the advice you are getting is coming from 2600K owners and their voltage ranges are different from the 2500K, their voltage ranges will not be the same as your 2500K, I suggest you take your advice from fellow 2500K owners,
but that's not meant as an insult to those attempting to help you. Ryan