exFat take up more space than Fat32

[Bryan Chee]

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[koreanlover]

I got a Fat32 500gb hardisk and a exFAT 2 tb hardisk,
when I backup the 500gb to the 2tb hardisk , the size on disk takes up much space - 2tb hardisk left only 200+ gb free space,

is this normal?

This is normal if you have a lot of small files.

Read here.

Use NTFS if you can.

 

[xtramadness]

Thank you for your reply.

I see.

Unable to use NTFS , as need to compatible for mac and window.

Mac can also be compatible with NTFS...

 

[davidktw]

This is normal if you have a lot of small files.

Read here.

Use NTFS if you can.

While this is normal for a large cluster size, that means a smaller cluster size should be chosen. TS please format your exFAT using 4K cluster size. Explicitly choose it if you need to. Large cluster size is useful if most of your contents are large media files or ios files or virtual machine images etc.

Normal usage of harddisk should choose cluster range around 4K

 

[jtjt00]

Please read post# 5 again as davidktw already mentioned the cluster size.

should i format my 2tb hardisk and rebackup everything again?
What is the allocation unit size i should set for exfat instead of default, lower or higher?

 

[Asure7]

I can understand files taking up more space due to bigger cluster size.
But for 500GB of data ballooning to > 1.5TB ... really? > 1TB of overhead?
Something doesn't seem right... if he really has that many small files, maybe even a 64-byte cluster size will be more appropriate :X


Anyway to TS: your answer is 4096

 

[Asure7]

TS: for normal usage, as mentioned by davidktw, you should be using 4KB (4096-bytes) cluster size. It will free up some space (but by how much, I don't really know... it depends on the type of files you have).

It's a matter of trade-off. If you have a lot of large files, a bigger cluster size can give better performance. Small cluster size can save space when you have many small files, but performance may take a hit with the bigger files.

If I'm not mistaken, the default cluster size for exFAT is 128KB for the hdd of your size. 4K is a very good balance, and already a smaller cluster size than what you would have on the FAT32.

 

[Asure7]

did u by any chance enable compression on the 500GB drive? Any hidden files?
FAT32 on a 500GB drive is not common (if it's a single partition) due to windows limitation.

Maybe you'd like to share what type of files you are transferring.
Or transfer one by one a few times to compare.

 

[Asure7]

Maybe you'd like to do a screenshot on the available allocation size, or verify the options you have again.
I noticed you mentioned 4096KB.. that is equal to 4MB (far too big).
You want 4KB (4096 bytes).

If 64 kilo-bytes is really your smallest option, use that instead.

 

[jtjt00]

How comes TS get smallest 64kb option. In Win 8.1, got option as low as 1024 bytes.

 

[mosmos]

oh, i did not know the exfat file format was so much difference~

 

[epos]

according to Microsoft, the default cluster size for 2TB is 128KB. I don't know if 3rd party partition software will allow you to manually configure the cluster size to 4KB.

http://support.microsoft.com/kb/140365

personally, I won't bother with exFAT unless I need to deal with Linux base OS. for Mac, you can install 3 files to allow OSX to access--read and write to NTFS partition.

NTFS-3G
OSXFuse
Fuse Wait.

https://discussions.apple.com/thread/5475310?start=15&tstart=0
read the post by Jirka_24u, and user feedback for more info.

I had tested it myself on Macbook Air, no problem whatsoever, write to the portable HDD is the same as from Windows.

edited:
heres a step by step guide:
http://www.thehyperlink.net/how-use-ntfs-disks-mac-os-x-mavericks