Formatting for ExFAT using Disk Utility

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Level 1

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Formatting for ExFAT using Disk Utility

On the web I have seen several warnings that if one formats an external HD for ExFAT using Disk Utility, it will still not work on Windows*. If you want a HD that truly works on both platforms - Windows and OS X - you need to format it to ExFAT from within Windows.

Has this issue since been resolved and can I now safely format to EXFAT using Disk Utility, or should I still do this on a Windows machine?

Thanks for any help on this.

*Vista and up, ExFAT is per definition not supported for earlier versions of Windows, and earlier versions of OS X for that matter.

Mac OS X (10.7.5)

Posted on Dec 5, 2012 12:43 AM

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Answer 1

baltwo

Level 9

62,386 points

Dec 5, 2012 10:38 AM in response to fifkikker

This might help, but there's no guarantees, since I don't do windoze: https://discussions.apple.com/docs/DOC-3044

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Answer 2

steve359

Level 6

17,187 points

Dec 5, 2012 10:41 AM in response to fifkikker

I formatted a thumb drive as ExFAT using OSX. Windows did not like it. I formatted the thumb drive as ExFAT using Windws 7, and *both* OSX and Windows like it.

Just a strange thing that Windows holds "something" back in its super-secret formatting of ExFAT.

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Answer 3

Kurt Lang

Level 9

68,532 points

Dec 5, 2012 11:39 AM in response to steve359

There's another thread here somewhere that explains it. OS X appears to be using too big of a block size. It's technically correct, but Windows doesn't like it when the block size is larger than 1024 KB. Formatting on Windows creates the disk/flash drive with a smaller block size that both system like. Unfortunately, OS X doesn't give you an option to pick a block size. It just uses a default in relation to the size of the drive being formatted.

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