In a word, yes.
There will come a point when a big jump in voltage is required for a small gain in clock speed. At this point, you've hit the maximum overclock that your cooler can handle.
My temps are reasonable though...my max is only 74c with an average of 69c. I am certainly not hitting a thermal wall.
I'm on a watercooler with a dual fan 240mm radiator, not air.
In any case it failed on 1.255 at the 5 hour mark this time.
I increased it to 1.27v and running again.
The BSOD's(101,124) correspond to a voltage, not thermal issue
My current settings are:
C States: Auto
Hopefully it is stable by the increase to Vcore this go around, but if it's not, surely theres something else I can tweak?