Which format to use exfat vs fat32 vs HFS+

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Level 1

4 points

Which format to use exfat vs fat32 vs HFS+

Hello,

i am about to purchase a new 27" iMac which will be my first full PC replacement. it will be a maxed out version, except that I up the drive to only 500GB but all SSD. I will use 1-2 external 1TB SSD drives as I am very concerned about backups as a hobby photographer and rather spread my risk than have it all on a single drive.

I Really want to make the switch to Mac OS, but will also install Windows as a backup. My research suggests that with boot camp I should reserve 30GB, and possibly more if I also need the entire Photoshop range under windows.

My question now is which format I should use for my internal SSD drive on the iMac: HFS+, exfat or Fat32? Are there any performance differences? I used Fat32 on an external disk for my MBA and am not impressed that file sizes are limited to 4GB max. Thus exFat looks more appealing. Does HFS perform much better under MacOS with respect to access time and transfer speed? Finally, would using exfat help me avoid partitioning my internal SSD between Mac OS and Windows? My concern is that once I set the partition, there is no way of changing the allocation later, unless I backup the entire Mac and reformat the entire SSD, or am I missing something here and one can change the allocation of partitions later on too?

BTW, I will also use 2-3 external disks which will be my travel backup drives for photos as I shoot them on trip and which I will use as expansions to my internal SSD drive when I am at home. Would it help using a more flexible exFat format for these, or is HFS+ best too?

will I be able to read any photos I saved on HFS+ when I use boot camp on my iMac to run windows, or does this only work if I used exFat for all my files?

thanks,

OLiver

Posted on Oct 19, 2015 12:18 PM

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Answer 1

Oct 19, 2017 9:58 PM in response to Kurt Lang

I had gone through the trouble of formatting in EXFat on MacOS and although I could both read and write through Windows XP Media Center Edition, it was spotty. I had more severe issues when I upgraded that computer to Windows 7. It was definitely read-only after that. So your explanation makes perfect sense. Thank you!

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Answer 2

Kurt Lang

Level 9

68,502 points

Oct 20, 2017 5:01 PM in response to mattlum11

You're welcome. 🙂

In reverse. If you format the drive as exFAT in Windows, don't choose a block size larger than 1024, or the Mac has trouble reading or writing to the drive. If the block size Windows chooses is lower than that (it usually is), just use what it suggests.

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Answer 3

JimmyCMPIT

Level 7

29,306 points

Oct 19, 2015 12:33 PM in response to OWimmer

Journeled extended for Mac

Mac OS X: About file system journaling - Apple Support

if you are installing Windows you will need a dedicated partition for it, you can't install on top of OS X. The windows installer will provide the correct format during installation.

FAT is for DOS, or sharing files between mac and windows and any other OS that can read it. FAT format does not keep permissions and ownerships. It's very outdated for OS's, it's great for flash drives and data drives when you share files, otherwise if you don't need to share you probably don't need FAT. FAT also has file more severe file size restrictions.

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Answer 4

Kurt Lang

Level 9

68,502 points

Oct 19, 2015 1:02 PM in response to OWimmer

30 GB is the default size Boot Camp Assistant will start with, but is woefully undersized. That barely holds Windows itself. I would suggest at least a 100 GB Windows partition for the OS, Photoshop and a decent amount of free space.

HFS+ (Mac OS Extended) is of course best for OS X since that is its native file format. If you need to write files that will be larger than 4 GB, then FAT32 is out. Use exFAT instead. For all intents and purposes, there is no file size limit, and the format is both read/write in Windows and OS X without the need for any third party software to access it. Format the drive as exFAT on a Windows drive. Windows doesn't always recognize a drive formatted that way on a Mac, even though you have the option to do it there.

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