the kernel you are using is default at 800 and is permanent. there are other kernels that will default at 600 with the settings above 600mhz being temporary or permanent (it depends which config you change) if you are worried about life and still wish to clock, it may be worth trying some of the low voltage kernels. titans "XLV ideal" kernel runs 850MHz at the same voltage that stock runs @500MHz. so if your phone is stable using the low voltage options i would go for one of those! the 125 bottom end seems a tad problematic also. altho this can be set higher in the configs should you desire.