F2FS is your better option (Yes I realise it wasn't in your question). If you use it heavily then you will eventually wear out a USB drive where you might not ever wear out of a hard drive. That's because USB flash drives have very low 'seek time', running Ubuntu from a flash drive is pretty smooth.Īs for wearing out a flash drive, this is more of a problem. This means that slow down due to reading data on disk is much less than you might expect when compared to spinning hard drives. This may speed up the otherwise slower file system considerably at the expense of CPU.Ī big proportion of OS IO is based on small file reads. For example btrfs supports transparent file compression. However benchmarks test quite narrow parameters which may not be reflected by running an OS. The benchmark I linked attributes this to copy-on-write behaviour of btrfs.
I've seen benchmarks (eg: this one) that put btrfs considerably slower than ext4.
