GUIDE: FAT16, FAT32, NTFS, or exFAT on USB Flash Drives?

[stewie]

FAT16, FAT32, NTFS, or exFAT on USB Flash Drives?
by stewie

If you don't feel like reading this boring guide and your thumb drive or partition is 2 GB* or smaller, then stick with the default FAT16 for best performance and cross-platform compatibility. There is a reason why most UFDs in these sizes, including my 4 GB stick, come pre-formatted with FAT16.

*Windows NT 4.0, 2000, XP, and Vista can support FAT16 up to 4 GB using 64K cluster size. However, it may create compatibility issues with some applications. But for storage purposes, it shouldn't cause any problems.

I just bought a USB thumb drive, which format should I use?

This question has been asked many times on NBR, many people are not sure about which one to use or suits their needs. In this guide, I will help you to understand the benefits and drawbacks for each of them.

Tools used for this guide:

• 1 GB USB flash drive
• Nodesoft Disk Bench (no synthetic results)

FAT16 (a.k.a. FAT)

Pros:

• Highest cross-platform compatibility
• Best overall performance

Cons:

• 2 GB volume size limit or up to 4 GB with some OSs
• Maximum file size of 4 GB (minus 1 byte)
• No access control and permissions (could be a pro)

FAT32

Pros:

• Good cross-platform compatibility
• No 2 or 4 GB volume size limitation

Cons:

• Moderate to slow overall performance
• Maximum file size of 4 GB (minus 1 byte)
• No access control and permissions (could be a pro)

NTFS

Pros:

• No 2 or 4 GB volume size limitation
• No 4 GB file size limitation
• Very fast write speed for single file
• Fewer disk accesses than FAT if a file is badly fragmented
• Access control and permissions (could be a con)

Cons:

• Low cross-platform compatibility
• Slow write speed for multiple files
• May have permission issues between users and systems
• May decrease the lifespan of the UFD due to additional writes
• Must remove the UFD with the "Safely Remove Hardware" procedure

exFAT (a.k.a. FAT64)

Pros:

• No 2 or 4 GB volume size limitation
• No 4 GB file size limitation
• Fast write speed for single file
• Requires less disk space overhead than NTFS

Cons:

• Very slow write speed for multiple files
• Cannot be used for Windows Vista's ReadyBoost capability
• No access control and permissions (could be a pro)
• Very low cross-platform compatibility
  (Currently only Windows Embedded CE 6.0, Vista SP1, Server 2008, and Windows 7. Drivers can be added to XP for read and write, but cannot format.)

Some test results with Nodesoft Disk Bench

Multiple tests were done for better accuracy, they were all done with the default allocation size, optimize for performance enabled, and antivirus disabled.

1 MB file | Read (MB/s) | Write (MB/s)

FAT16 — 32.393 — 2.063
FAT32 — 32.393 — 1.339
NTFS — 32.393 — 2.797
exFAT — 32.393 — 1.464

10 MB file | Read (MB/s) | Write (MB/s)

FAT16 — 129.334 — 4.645
FAT32 — 129.334 — 3.943
NTFS — 129.334 — 29.326
exFAT — 129.334 — 4.703

100 MB file | Read (MB/s) | Write (MB/s)

FAT16 — 306.212 — 5.106
FAT32 — 306.212 — 5.065
NTFS — 321.915 — 4.952
exFAT — 379.010 — 5.188

Writing 50 MB of 712 files and 95 folders

FAT16 — 1 min 12 sec
FAT32 — 1 min 19 sec
NTFS — 1 min 50 sec
exFAT — 1 min 55 sec


Conclusion

If you're reading/writing a single file, NTFS seems to win hands down. But in real life situations where multiple files being read and write, then it's another story, NTFS was more than half a minute slower when writing just 50 MB of multiple files and directories.

For some reason, the reading times from Disk Bench seem to be pretty much the same between the file systems, I'm not sure if they're accurate, but many other test results on the Internet (e.g. Irongeek.com, AnandTech.com) have shown that FAT16 to be the quickest as well, although the difference becomes less significant for bigger files. If you have done some tests with your UFD, please feel free to post them.

EDIT:

exFAT added.

[Andy]

Nice Guide Stewie.

NTFS

Pros:

• No 2 or 4 GB volume size limitation
• Very fast write speed
• Fewer disk accesses than FAT if a file is badly fragmented
• Access control and permissions (could be a con)

You could add "No 4GB (or GiB) file-size limitation".

I have a 4GB FAT32 formatted flash drive, and I use it only for documents and all. Can't have 4GB+ files on it anyway.

[stewie]

Thanks, Andy. No 4 GB file size limitation added.

[TehSuigi]

Very nice guide! I've now reformatted my 2GB USB drive to be FAT, and I'm going to change my 8GB from FAT32 over NTFS.
Say, do you have any benchmarks for a UFD using the exFAT file system?

[stewie]

Very nice guide! I've now reformatted my 2GB USB drive to be FAT, and I'm going to change my 8GB from FAT32 over NTFS.
Say, do you have any benchmarks for a UFD using the exFAT file system?

Thanks, TehSuigi. No I haven't done any benchmark on exFAT yet, it's a good idea though, I should add it later this week. Right now, only Windows Embedded CE 6.0, Vista SP1, Server 2008, and Windows 7 fully support exFAT. There is a way to add the drivers to XP for read and write, but it still won't let you format a new drive to exFAT.

[Spare Tire]

Wait a minute, why does fragmentation matter on a flash drive?

[stewie]

Wait a minute, why does fragmentation matter on a flash drive?

Actually, it does. Here are a couple of good articles.

http://www.reuters.com/article/press...008+MW20081028
http://www.diskeeperblog.com/archive...pact_of_f.html

[Spare Tire]

Just skimmed through the articles. Yes, i can imagine that free space fragmentation would cause a slowdown during writes because flash writes to blocks of what, 2 megs at a time? You're right. Read though, shouldn't be affected.
I suppose diskeeper wants us to defrag our flash drives huh?. Instead, just swap all the content to your hdd, then swap it back will do the trick without the additionnal write cycles of moving things on the flash cell itself.

[stewie]

Just skimmed through the articles. Yes, i can imagine that free space fragmentation would cause a slowdown during writes because flash writes to blocks of what, 2 megs at a time? You're right. Read though, shouldn't be affected.
I suppose diskeeper wants us to defrag our flash drives huh?. Instead, just swap all the content to your hdd, then swap it back will do the trick without the additionnal write cycles of moving things on the flash cell itself.

I just noticed the second article is by diskeeper, it's probably a bit biased. I found another article with some test results, although they did pointed out about this same diskeeper article, but at least they did their own tests.

http://www.lagom.nl/misc/flash_fragmentation.html

Yeah, swapping the files should do the trick.

[stewie]

Very nice guide! I've now reformatted my 2GB USB drive to be FAT, and I'm going to change my 8GB from FAT32 over NTFS.
Say, do you have any benchmarks for a UFD using the exFAT file system?

I just added some results for exFAT.