EDIT on 02/16/2011 – It works again! 10.6.6. Seems the bug was ironed out on 10.6.6. Thanks all who reported it. I didn’t have the chance to test it out on a Win7 machine (as I was fresh out of one).
EDIT on 12/09/2010 – As Clinton pointed out in the comments below, a partition formatted in OSX as exFAT will in fact not work on Windows 7. You can however, format the partition in Windows 7 as exFAT to make it r/w on OSX. Sorry for this! I will update when I know more.
What a wonderful surprise last evening with the release of 10.6.5, especially for us dual-booters – support for ExFAT in OSX! Windows 7 and Vista SP1 have supported it for months, as did the 27″ iMac (mid 2010), but with 10.6.5, this has been released for all. The possibilities are just mind-boggling.
For the first time ever, native support for reading/writing files on a partition by both OSX and Windows! This has been a pipe dream, that has worked dodgily at best. One has had to resort to MacDrive on Windows to read/write OSX partitions, and poor OSX folk have had to wrestle with NTFS-3G drivers – don’t even get me started on how much I hate NTFS-3G. But with ExFAT, OSX and Windows 7 can work with the same partition with no extra software required. Wow. Just wow.
To get started, just format a partition on your drive, either on OSX or Windows 7 in ExFAT and watch the fireworks! Things like these bring out the geek in me. This alone is worth the update to 10.6.5. GO GET IT!
Do you know if formatting the drive to exFAT on the mac, still makes it usable from Windows 7? I’ve heard some complaints that it doesn’t, and wanted to know your personal experience before I go formatting my drives. :-)
Clinton, thanks. I can confirm that drives formatted in OSX as exFAT don’t actually work on Win7. The other way round is correct though. Format your drives as exFAT in Win7, to make them writable in OSX. I haven’t been able to figure out why this happens.
Thanks for bringing it to our attention!
I just formatted a 640 GB USB drive as exFAT using Disk Utility on OS X 10.6.6. I can successfully read/write the drive on both Mac OS X and Windows 7. Perhaps the 10.6.6 release fixed the formatting/Win7 issue described in this article.
I’ve just tested it between Mac OS X 10.6.6 and Windows 7 Ultimate (64-bit), and the result is, no, one still cannot format partitions under OSX and use them afterwards under Windows. They won’t be recognised. Only the way around does work. What is also somewhat peculiar is the fact that Windows is unable to format mounted Truecrypt partitions with exFAT, that is, if one encrypts a partition with Truecrypt, but does not format it, and later tries to do it with means of Windows’ onboard-tools. It works only with FAT, FAT32 and NTFS. However, it can be done under OSX as far as I remember.
What are you guys smoking? I formatted under OSX and it WORKED with both Vista and Win7!
I’ve also formatted drives as exFAT with a mac and had no problems with Windows 7 using it. If it’s not working for you something else is going on.
Thanks all, it does work on 10.6.6. The bug seems to be fixed in the latest iteration.
I’ve formatted exFAT RAID 1 array on MAC OS X 10.6.6 (2 x 2TB), but no matter what technique I use, half way through transferring 1.2 TB of files from my old computer to the new one, it slows down to a snail’s pace… Could exFAT be implicated?
Not playing nicely here. I had a 2TiB exFAT volume which refused to work with XP/Vista and 7.
5 minutes ago I re-formatted with 10.6.6 and lo-and behold… it still didn’t read under Vista or 7. So I tried formatting as exFAT under Win7 and it’s working properly across all platforms.
Seems that 10.6.6 doesn’t fix everything…
@Clockwork: Me too. I’ve got a TON of data on this disk, and it won’t mount under win7. I’ll try and remember to update here if I find a fix :(
Just formatted my new 3TB external drive on my Mac OS 10.6.7 machine using exFAT and its unreadable in Win 7 for me. That sucks.
I then formatted the drive using exFAT on my Win 7 machine and it works perfectly fine on my Mac and PC. I’m glad its working now but it sucks I can’t just format the drive on my Mac and have it readable on both platforms.
I also had problems with Disk Utility creating an unreadable drive, but was able to get it working.
If you are using the Partition tab to create a partition and use the disk from there, DON’T! It will work in OS X, but not be usable in Windows.
See the screenshot above…the trick is going to the Disk Utility “Erase” tab, selecting exFAT there and clicking “Erase…”.
…also, I did this in OS X 10.7.1 (Lion).
Hi,
i got a workaround working for this problem:
I am sorry my blogentry is in german (google translate):
http://translate.google.de/translate?js=n&prev=_t&hl=de&ie=UTF-8&layout=2&eotf=1&sl=de&tl=en&u=http%3A%2F%2Fwww.web-dreamer.de%2Fblog%2F2011%2F08%2Fmac-os-x-und-das-exfat-problem-mit-windows-jeweils-nur-in-win7-oder-mac-lesbar.html
in general it works if you use diskutil…