Alex "Tell it like it is"
Needs little to no formatting and I have yet to see a SanDisk fail. Don't cut corners, almost every other brand of SD cards will fail on you except these (tried numerous brands with my devices).Just remember it takes a bit for devices to buffer the information off of the SD card and static can corrupt any SD card which is usually easily fixed with a formatting. Always back up your documents to a PC/Mac as soon as possible.Oh, and if you create playlists, slideshows, etc. on devices and remove the SD card, the device will not be smart enough to re-compile it after you put the SD card back in and you will end up with blank playlists even though you have the songs so WATCH OUT!Lastly if this SD card doesn't work for you for whatever reason google SD card formatting and it should help you out. These 64GB versions don't seem to have formatting issues like the 32GB ones do but even then formatting to FAT32 fixes it.