We’ve put considerable effort into controlling the amount of writing the emonPi does to an SD card to prolong SD card life. The results seem to be pretty good, we’ve had SD card running for a number of years without any issues. However, there has been occasional reports of SD cards failing prematurely. Especially after power cuts.
We usually use standard Kingston SDCS2/16GB micro SD cards. Frustratingly SD card datasheets don’t quote expected write limits.
I’m considering doing some testing with ‘industrial grade’ SD cards to see if they offer any improvement in durability. This is obviously a difficult test to do since way may not know the result for 5+yrs!
From my limited research I’ve established that most ‘consumer grade’ SD cards have MLC NAND flash, industrial SD cards generally have SLC NAND flash which is quoted to achieve 10x-30x more writes. Here’s a detailed comparison between the two types of NAND. Unfortunately SLC SD cards command a 10x price increase over standard MLC SD cards of comparable size.
The lowest cost SLCD micro SD cards I’ve managed to find are:
Has anyone got any experience using and testing ‘industrial’ SD cards?
Update: I’ve created a poll to collect data on the longevity of our current SD cards.