Micro SD card help
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Hi I use 2 micro SDcards as a failsafe storage system-
Both cards are 64gb.
One card is now saying the capacity is 57gb so it's not correctly taking my images.
If I reformat the card it's blank but still says max capacity is 57gb.
Any suggestions on how to sort this card out?
I've just brought a second Pi I'm raring to get this fixed.
Thanks -
@mattyl42 Basically, that's normal since storage media manufacturers considers 1GB = 1,000,000,000 bytes. But digitally your computer system counts 1GB = 1,073,741,824 bytes. Thus, your system reports 59.6 GB +/- instead of 64.0GB. This difference between the two is where the space is "lost", it actually isn't lost, it was never there to begin with. Each "step" up in naming you lose 2.4% of space (the difference % between 1000 and 1024). So you can do the sums.... multiply your original 64GBs by .976 (1.000 - .024), where 1.000 = the whole part.
The "loss" at kilo is 64 * .976 = 62.464.
The "loss" at mega is 62.464 * .976 = 60.964864.
The "loss" at giga is 60.964864 * .976 = 59.5~.
Remember that a very small amount is reserved for the file allocation table, and other overhead for maintaining the file system on the drive itself (recycle bin, volume info, etc...) -
@rbaker
Thanks for the detailed description -
The same also applies for hard drives. You will never get what the actual size is quoted due to filesystem overheads and lose even more space depending what filesystem you format them to. Some take more space than others, some are very efficient filesystems, some are not
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