Is it mandatory to "prepare" an SD card for use with the Pi?

The SD Card setup page on elinux contains "information on how to prepare the SD Card used to boot your Raspberry Pi", and it states that I have to use a special SD formatter and activate a "FORMAT SIZE ADJUSTMENT" option.

What is it and what does it do? How is that different from just formatting on Windows? I have used both FAT16 and FAT32 SD cards preformated from factory and this option didn't seem to change their filesystems.

  • 2
    I haven't used NOOBs which you linked to, so I would recommend going to the next section "Using Windows 7 or Windows XP -> Using the Win32DiskImager program". If you follow that part of the guide through, you can't really go wrong. Also: "Preparing" the SD card just means putting the correct distribution on there, and making it boot-able, which is what the step above covers.
    – v25
    Aug 12, 2013 at 13:19
  • The special SD card formatter is used to return your SD card back to it's original factory condition (that way a camera, a phone, or anything that uses an SD card for storage could use it). "FORMAT SIZE ADJUSTMENT" erases all of the partitions that are on the card from previous devices it may have used it.
    – slippery
    Aug 14, 2013 at 15:53
  • @zeldarulez can you provide a source? Sep 2, 2016 at 17:38

2 Answers 2


When you use something like Win32DiskImager to prepare an SD card, all you are doing is taking the image file of the distribution you want to use and applying that image to your SD card.

If you have used DD, this is basically the same process. The Image files of all of the RPi distros contain a FAT16 partition and an EXT3 partition (versions of FAT and EXT might vary from distro to distro). You are just laying down the image onto the new disk, making it an exact copy of the developer's disk. On first boot you should have an option to resize the EXT3 partition to fill whatever space your SD card has left.

The NOOBS instructions are just formatting the whole card to FAT16, and copying a FAT16 based distro onto it. (rather than splitting the SD card into a FAT16 '/boot' partition and an EXT3 Linux '/' partition. The advantage of using the SD card formatter over Windows' built-in formatting is that the only option is to format it as FAT and it will only let you format an SD card so there are fewer ways for a N00b to go wrong with the NOOBS instructions. If you are using a brand new SD card you shouldn't have to use the Format step at all, it should be ready to roll. Just copy the NOOBS files onto it.


FAT32 should work fine. All you need to do is:
1. get a free disk image utility (such as UltraISO)
2. get a Linux distribution that is compatible with the Pi (in .ISO/.IMG format)
3. mount the distro on the flash card via said image utility (do not simply drag/drop the contained files to the root directory)
4. boot the Pi with the flash card in it

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