It's not an issue with the board, it's just normal. Every board from every brand overvolts on auto, and the higher you oc the worse it gets. It's why you don't use auto vcore when overclocking, unless maybe for a very mild oc and then it's still not optimal.
[answering 2is]
Yes, but it's less wrong than what Morbus was saying. 50 or 60 degrees is nothing for a cpu and temps like that will surely not cause any meaningful degradation, unless with 'over time' he means 20 years.
Intel website is just confusing for starters as well, listing the 72 degree tcase value when no software can actually read that value. The only thing we do know is that at normal clocks and voltage 99 degrees is the thermal throttling point.
Personally I don't mind seeing 90 degrees during Linx stresstesting, normal temps will be way lower anyway.
I settled on my 4.6Ghz clock for this now-dated Sandy Bridge core when I saw the four core temperatures hovering around 76C under a punishing LinX test. Generally, my ambient for those tests was between 78 and 82F.
I'm only guessing that the IHS (integrated heat spreader) for Ivy and Haswell cores is not too different than it was for SB. It's copper with nickel-plate. TCase was supposedly defined to measure temperature at center, and it was always so many degrees -- maybe 10C below an average for the core sensors.
Of course, all that changes with Intel switching from a solder applied between the IHS and the silicon, to a thermal paste. With the understandable risk, replacing it with liquid ultra would again reduce the difference from a hypothetical TCase. But I'll agree with everyone else: there is some modest interaction between voltage required and temperature, but the ill effects are two different things.
Certainly, I might expect greater risk with higher temperature with the more-compact Haswell (what is it -- 16nm or something like that?)
Anyway, a 4.3 clock (if achievable) on a Haswell might mean better performance than a 4.6 or 4.7 on an old Sandy. And somewhere I and some others already remarked that we're less gung-ho on OC'ing the newer cores.
Then, there's the ability to enable the power-saving features with an overclock setting. Since additional speed also generates additional heat, but you're only running full-out at those speeds for some fraction of the time the processor is powered throughout its lifetime, the voltage damage risk would be more attributable to the spikes in transition -- unless the turbo-voltage setting is way beyond a range around default.
It seemed that the spikes were cited as a greater risk in the Yorkfield article a few years ago. With a fixed VCORE, you are just applying a higher voltage continually, and you still experience the spikes.
But again -- point of it -- these last three generations of cores were designed with a "turbo mode." They made the chip smaller and reduced the power requirement. The default clock speeds have changed very little over the three lines of processors. So it now seems less useful to OC -- just for a few hundred Mhz.
EDIT: Memory fades! That is -- my own! The lithography for Haswell is same as Ivy Bridge or 22nm? I see now [about six months tardy]. The TDP is lower at 77W -- same lithography. I'd only guess that higher voltage is the bigger risk with that. . . . If you're going to OC, you might want to impose a more severe limitation on over-volting VCORE. And [EDIT] -- maybe SOME processor models have lower TDP, but I now see the 4670K at 84.