I bought a XFX 8600GT Extreme Edition card, which was overclocked to 650 Mhz core speed from the original 530 Mhz. now i am afraid about the life time of the card. Is it really safe to use an overclocked card ?
Don't worry. XFX has life time warranty, so in case it does die, you can return it for a new one. They can't tell you OC'ed it or not.
^+1. @OP: Just curious what did you pay for that 8600GT card?