02-01-2019 05:46 AM
02-01-2019 09:53 AM
Flash drives are made with blocks of error recovery sectors so that if a good sector gets damaged for some reason it is flagged and a recovery sector is allocated in it's place. Does this add overhead, yes, but it beats the other option.
Another thing that can change allocated sectors, partitioning. Type of partition, alignment of the partition. Same goes for formatting.
If you think one drive is damaged, return it for a free replacement.
Important files = Backed up files