I'm hitting 3.8GHz at 1.168v. Idles at 50 degrees and hits 78 degrees while prime95'ing overnight. I can do 4.0GHz stable, but that requires a bump to 1.3v.... why the huge jump in power needs for only a 200MHz gain?
To be honest it is too technical for me to understand fully. It has a lot to do with the physics of transistor junctions etc. But it is a common thing, for a while you can get almost anything to perform better with minor tweaks but there comes a point where major work has to be done to get more. The increase in performance is not linear, diminishing returss kicks in at some point. A car might be a good analogy, cold air intake, headers, performance car computer chip gets you lots of extra horsepower without major effort, but then all of a sudden to get more you are looking at $1200 cylinder heads and expensive engine work and at some point instead of major horse power gains you are looking a big bucks for little gains.
You have found the sweet spot. Many of us use that point to back off a bit and call it quits as the stress on the system is not worth the minor gains. And then there are the other people.... its your stuff and your call. If you have tried the other chip voltages etc. and still require that big voltage jump there is not much you can do about it but to decide if you want to go there or not.