No idea. Every cpu has a standard speed guaranteed to be stable by either amd or Intel. Once you OC, the guarantee for stability goes out the window. There is a thing called the cpu lottery. Every cpu is part of it, but the stock speed cpus are the only cpus that win 100% of the time. For OC, once you go above stock speed, even by as little as 100MHz, you run into the possibility of instability, bluescreens. Some cpus do better than others. I have a i5-3570k that runs great at 4.3GHz at 1.14v but will not in anyway be stable at 4.4GHz even at 1.42v. I've seen other 3570k's reach 5.0GHz, I've taken my 3770k to 4.9GHz at 1.32v so I should be able to reach 5.0GHz at @ 1.4v,never bothered to try.
Basically the cpu lottery states that any given cpu will only go so high, with so much voltage and it's all dependant on that particular cpu, not any other, even the exact same model. Same goes for gpus.