fastest format for sdxc cards
Formatting an SDXC card for use with NOOBS. According to the SD specifications, any SD card larger than 32GB is an SDXC card and has to be formatted with the exFAT filesystem. This means the official SD Formatter tool will always format cards that are 64GB or larger as exFAT. The Raspberry Pi's bootloader, built into the GPU and non-updateable, only has support for reading from FAT filesystems (both FAT16 and FAT32), and is unable to boot from an exFAT filesystem.