Personally I think you should use manual controls for OC but that's not what you asked.Anyway 73c on IBT is not bad but don't let it run much higher
Thanks, I would love to know if there is any tutorial that would help me to get around the bios settings, the new 3D bios is a little confusing, and i can't find a tutorial for OC'ing 2700k on Gigabyte z77 bios.
73c for only a 4.3ghz clock seems high to me with a Noctua NH-D14.
54.25c @ 5.0ghz, but I have much better cooling than you do, plus I'm manually overclocking.
Sometimes the auto overclocking features, utilize way too much operating system voltages, on auto I've seen voltage spikes to 1.520v, which is Intels tested max limit, have you used CPU-Z and monitored what your voltages were actually running in the operating system?