SanDisk SD cards come prefomatted as FAT16, FAT32 & exFAT according to size
- 2GB FAT16
- 4GB to 32GB FAT32
- 64GB or higher exFAT
If you have a SanDisk Wireless Flash Drive or SanDisk Wireless Stick
- 16GB & 32GB SD cards must be formatted as FAT32
- 64GB and higher capacity drives are compatible and can be formatted as exFAT
If you are still having problems try reformatting them with EaseUs Partition Manager
or windows disk manager
if none of the above work you can get a replacement SanDisk Wireless Flash Drive or SanDisk Wireless Stick from SanDisk
What is the difference between Class 4 and Class 10 SD HC Memory Card speeds ? I just copied a 3G image using Win32DiskImager to two 16G SD HC cards one Class 4 and the other Class 10 (but labelled 30MB/s) both from ASDA.
The speeds / times were as follows
- 16G C4 averaged ~ 4MB/s and took ~10 mins
- 16G C10 averaged ~ 10MB/s and took ~4 mins
So maybe it really is worth paying twice the price for 2.5 times the speed !