I recently upgraded my pc, and I grabbed a cheap titan (original) with waterblock off ebay. I'm looking to overclock and overvolt it, but I don't want to shorten the lifespan of this card. I'm looking for it to last 5 years, and 8 years at the most. I have it overclocked to 1070mhz on the core, and 7ghz on the memory. I haven't touched the voltage at all though. It is currently bios modded, and has a full cover EK waterblock. How much can I overvolt the card before the lifespan decreases below my target?