Which is the best format for a USB drive? I tested a 500 GB USB-2 hard drive using Ubuntu 13.04. Here are my speed / access time results,

Format.........FAT32........NTFS........Ext4...... .Units

Read Speed...27.5.........27.8.........28.0........MB/s
Write Speed..21.5.........21.7..........21.3.......MB/s
Access Time..17.47.......17.52.........17.35.....ms

So is there any real difference here? The differences are small and I suspect that if I did a re-test, the differences would change around. So which is the best format?

I use Ubuntu, Mint and Virtualbox for XP. All work OK with any of these formats. Perhaps FAT32 and NTFS may need degrags whilst Ext4 does not - is this correct? To defrag I'd have to do this through a XP VM. What other criteria differentiate these formats?

Thanks in advance!