Life span of a card depends more on what you are doing and how hard you are on the card and adequate air flow so the card does not overheat. The only cards I have had die were doomed to fail due to heat issues either from the setups the cards were installed in, improper installation without thermal paste, or poor or damaged heat syncs. If you buy a major brand with a good track record and don't abuse it, it should last as long as the computer does. That being said, if you are looking at over clocking or have more specific needs in mind than type of card can make a huge difference.