I've been curious for a long time about the way these filesystems compete with each other. I know they are not the most advanced systems out there and hence not the most interesting. Nevertheless, over the time i've seen various benchmarks that focuses only on performance and perhaps aren't the best way to do the comparison. For example, when Phoronix compares UFS2 as implementented on FreeBSD and EXT4 on Linux, they do with the default options (that is, UFS without async). Some say this is comparing apples with oranges. Is it so? Is default EXT4 then inherently less 'secure' than UFS in terms of data integrity? Or is it both fast (async) and 'secure'? Would UFS2 be as 'fast' with async? Why are apples being compared to oranges? I would like to know the technical arguments behind the claims. Specifically, UFS2 as implemented by FreeBSD compared to EXT4 as implemented by Linux.