PREFACE: I would appreciate answers accompanied by facts and references. While I respect pure opinions, they don't seem to comply with the rigorous requirements of superuser.com forum.
How long is the service life of an SD card?
One often-cited number is "10 years" (for example here).
On the other hand, many manufacturers cite their products expectancy in hours, for example SanDisk® High Endurance microSD™ Card is listed as 20,000 hours (and this number is viewed as "high"). However, 20,000 hours equals to only 2 years and 3 month.
I know that longevity of flash memory can be limited by the following factors:
- Write cycles (irreversible damage);
- Charge leak (loss of data, but no damage);
- Hardware degradation (irreversible damage);
So, my question is - in an "occasional write" scenario, how long it would be reasonable to expect SD cards to work?
I have some flash drives, SD and CF cards that are older than 10 years, and they still seem to be good. Should I throw them out just as a precaution?
A question What's the life expectancy of an SD card? contains some useful information, but it is focused on the number of write cycles, and not so much on time in the absence of writes.
Also, consider the following scenario: An SD card is certified for 100,000 writes (just assume this is a fact for argument sake). Someone is writing to this card once a week. Should we expect this card to last for 1900 years?
P.S. I am puzzled to see why my question is viewed as "subjective". For comparison, life expectancy for U.S. in 2019 (for humans) was 78.87 years - and there's nothing subjective about this number. For water heaters, life expectancy is 8-12 years (a significant range, I admit, but still a numerical range). Why average flash memory characteristics are believed to be "subjective"?
