die temp or core temo

Thats a good question. Though I believe it's die Temp.. If the cores are getting hot, that means the Die temp will be even higher.

70c is close to 150 or 160f so, at that point the silicon in the die is literally starting to bake itself and will likely cause dmg.
 
either way 70C is way too hot. 60C is considered cooking for most people. If those are your temps u should consider getting some thermal paste w/ a better hsf, more case fans, or water cooling.