What is the block size for writing to a flash drive (the minimal size that gets erased and rewritten)? Does it depend on the block size the drive was formatted by, or is it independent of that?

Does the drive rewrite a block every time I hit "save" on a document, or does it remember the changes and write them when I click "eject drive"? Does it matter if it's NTFS or exFat?

My goal is to minimize drive wear. I can format the drive with any file system, and I can copy documents onto my computer before work and copy back after, but would rather not do that if it's not needed.

  • i'm not expert and I can't answer much of that but I guess it depends totally and only, on file system. You could test formatting it as different file systems and making a one byte file, just one character in it. But then go to properties and near size it says "size on disk" and if it's NTFS you'll see that's 4KB (tested in win7 so NT 6.1) (though NT 3.51 was different) – barlop Jun 26 '16 at 12:28
  • Save will save them, it doesn't only save them when you eject the drive! You can view the files on the drive after a save.. see the file size increase. A person could pull it out after a save without ejecting and would see it. Also you might find that some usb keys are better built and last longer than others but I don't know details re that. – barlop Jun 26 '16 at 12:34
  • @barlop Read up on the flash drive block I'm referring to here. – ispiro Jun 26 '16 at 14:22
  • Filesystems typically offer multiple block sizes. Also note that read blocks may differ from write blocks. In a sense wear-leveling also depends on the controller chip and possible caches the drive uses. Sector alignment may also play a role. – jiggunjer Jun 26 '16 at 15:34

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