I am new to overclocking video cards and just need to know some info on it. My first question is: Does it harm your card's lifetime? Is it dangerous to do to it? Is it better to have it constantly overclocked or to just OC it when you need to? Also, I know that I need to have riva tuner. And my card is a MSI NX8800GTS 512. I want to OC but am wondering how much it will harm my card and how to know if it's stable? Thanks