Formatting USB drive - FAT32 allocation unit size

Discussion in 'Mac Apps and Mac App Store' started by deep diver, May 3, 2012.

  1. deep diver macrumors 65816

    deep diver

    Jan 17, 2008
    Solon, OH
    I have a 64GB Corsair Flash Voyager GT thumb drive (USB 3.0, compatible with USB 2.0). I need to format it in FAT32 as a single partition. The allocation unit size must be 4Kb. I know how to format to FAT32 but Leopard (OSX 10.5.8) does not have an option for choosing the allocation unit size. Is there a utility that will allow me to do this?
  2. MisterMe macrumors G4


    Jul 17, 2002
    Why do you need to format to FAT32? Virtually every Windows computer and nearly every Mac with an NTFS driver installed can read and write NTFS.
  3. Grannyville7989 macrumors 6502a


    Aug 2, 2010
    Why do you want to adjust the allocation size of the file allocation table?
  4. Bear macrumors G3

    Jul 23, 2002
    Sol III - Terra
    Have you tried formatting it on Leopard to what size allocation unit it uses?

    Not everyone wants to be bothered installing NTFs drivers on their Mac. Of course with an allocation unit size requirement, it sounds like it might be being used to plug in to a device besides a computer.
  5. Moonjumper macrumors 68000


    Jun 20, 2009
    Lincoln, UK
    ExFAT works on both Windows and Mac without any drivers and doesn't have the size limits that FAT32 does.

    I don't know if it works in Leopard, but it is now one of the standard Lion formatting options in Disk
  6. Bear macrumors G3

    Jul 23, 2002
    Sol III - Terra
    ExFat support was added as of 10.6.5, so no it isn't there in Leopard.
  7. GGJstudios macrumors Westmere


    May 16, 2008
    This might be helpful:

    Format A Hard Drive Using Disk Utility (which is in your /Applications/Utilities folder)

    Choose the appropriate format:

    HFS+ (Hierarchical File System, a.k.a. Mac OS Extended (Journaled) Don't use case-sensitive)

    NTFS (Windows NT File System)
    • Read/Write NTFS from native Windows.
    • Read only NTFS from native Mac OS X
      [*]To Read/Write/Format NTFS from Mac OS X, here are some alternatives:
      • For Mac OS X 10.4 or later (32 or 64-bit), install Paragon (approx $20) (Best Choice for Lion)
      • For 32-bit Mac OS X, install NTFS-3G for Mac OS X (free) (does not work in 64-bit mode)
      • For 64-bit Snow Leopard, read this: MacFUSE for 64-bit Snow Leopard
      • Some have reported problems using Tuxera (approx $36).
      • Native NTFS support can be enabled in Snow Leopard and Lion, but is not advisable, due to instability.
    • AirPort Extreme (802.11n) and Time Capsule do not support NTFS
    • Maximum file size: 16 TB
    • Maximum volume size: 256TB
    • You can use this format if you routinely share a drive with multiple Windows systems.

    exFAT (FAT64)
    • Supported in Mac OS X only in 10.6.5 or later.
    • Not all Windows versions support exFAT. See disadvantages.
    • exFAT (Extended File Allocation Table)
    • AirPort Extreme (802.11n) and Time Capsule do not support exFAT
    • Maximum file size: 16 EiB
    • Maximum volume size: 64 ZiB
    • You can use this format if it is supported by all computers with which you intend to share the drive. See "disadvantages" for details.

    FAT32 (File Allocation Table)
    • Read/Write FAT32 from both native Windows and native Mac OS X.
      [*]Maximum file size: 4GB.
    • Maximum volume size: 2TB
    • You can use this format if you share the drive between Mac OS X and Windows computers and have no files larger than 4GB.
  8. deep diver thread starter macrumors 65816

    deep diver

    Jan 17, 2008
    Solon, OH
    Thanks everybody. My need was very specific. I got a new car and wanted to use a 64GB drive with my audio system. The car could not read the drive. After some searching, some folks said they got drives that size to work after reformatting to those specs. Disk Utility does not allow the user to choose the size of the allocation unit. Last night I did the formatting on a friend's Win7 machine. Still did not work. Exchanged the drive for another brand. No good. Returned that and got a 32GB. That one works just fine.

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