I want to clarify things: in the talk I have preferred to warn people against the worst case scenario - which can well happen. Damage to the silicon happens when the system is forced to run in overdrive mode (550&600) constantly, because of the extra voltage required by these operating points. Tampering with these sort of settings puts the system out of its supported operating range. Edit: But normal usage is ok and only those who are planning to do 24/7 number crunching on their phone should be worried.