Power7 has a kind of dynamic overclocking, see this pdf: (it adjusts clock and voltage to maximize performance or save power): http://scholar.google.com/schola

Power7 has a kind of dynamic overclocking, see this pdf: (it adjusts clock and voltage to maximize performance or save power): http://scholar.google.com/scholar_url?url=http://www.cs.binghamton.edu/~millerti/cs680r/papers/Timing/ActiveManagementPower7.pdf&hl=en&sa=X&scisig=AAGBfm2n9GzOcGs3tj8u4y2jxnYU7CdAGQ&nossl=1&oi=scholarr http://scholar.google.com/scholar_url?url=http://www.cs.bing... The paper does mention aging.. I suppose this circuit could compensate by boosting the voltage, but this would cause you to hit a power dissipation limit at lower performance, so I think the chip will indeed end up being slower over time.