The Mining cards tend to have a bit of wear and tear, as they are under strain a lot. That said Graphics cards are pretty robust, and can certainly take a beating. Having doing mining currently, my card still runs great even though what I have put it through, it's been heavily overclocked and since the first time I have bought it, still performs roughly the same. You'll find at by the time the card does have it's final days, it's tends to be extremely outdated by then, but it all depends on the card.