Today’s Question: I always use the same card in my camera (not a choice, just lazy). Should it be rotated with other cards for longer life and less chance of failure, or does it matter?
Tim’s Quick Answer: I wouldn’t worry about rotating among several cards, as long as you replace your cards periodically and don’t ignore any signs of possible corruption.
More Detail: Media card are generally very dependable. If they are going to fail, they will most likely either fail very early on due to a manufacturing defect, or fail when they reach the end of their useful life. Rotating among cards won’t provide much benefit, other than the fact that it means it will take longer to get to the end of the useful life for a given card.
When I refer to the end of a cards useful life, that generally means reaching the maximum number of write operations for the memory of the card. That generally translates into 100,000 write cycles or more. However, that doesn’t quite convey how long it would take (on average) for a card to fail. That is because media cards use strategies such as wear leveling to help balance out the use of the memory blocks on the card and help extend the overall life of the card.
In other words, as long as you don’t happen to get a card that fails early, odds are you’ll replace a card long before it would otherwise fail. That might be because you want more capacity, you need a different card type for a new camera, you lost a card, or any other reason. The point is, in general media cards will last a long time, and switching between various cards won’t provide any significant benefit in terms of the potential of a given card to fail early.