2014-07-08 12:22 GMT+02:00 Jon Severinsson <j...@severinsson.net>: > Am 06.07.2014 21:47, schrieb Lennart Poettering: >> BTW, have you checked whether reuseing the XZ context might make the XZ >> more competitive? > > On Sun Jul 6 15:01:11 PDT 2014 Reindl Harald wrote: >> please try a simple test compress 50 MB with XZ and GZ, LZO, LZ4 >> or BZIP2 - XZ is *magnitudes* slower in any case > > Actually it is not, or rather, it is only that if you want it to be that. > I did a quick comparison using the systemd 214 tar (30 MiB): > xz -0 was 28% slower than lz4c -hc, but the result was 19% smaller. > xz -0 was even 44% faster than gzip -9, and the result was still 5% smaller. > >> XZ is the wrong compression for anything where user feedback in time matters > > No, xz -6 is the wrong compression *setting* for that use-case, but at a lower > setting xz is quite suitable even for that. > >> even with no care about memory usage which also is part of the game finally > > xz -0 needs about 3 MiB for compression, hardly a prohibitive requirement. >
For comparison, this is what I get when running it on my laptop for 210 (a tarball which I had lieing around): xz == $ time xz -6 systemd_210.orig.tar real 0m9.573s user 0m9.520s sys 0m0.044s $ du -hs systemd_210.orig.tar.xz 2,6M systemd_210.orig.tar.xz $ time xz -0 systemd_210.orig.tar real 0m0.951s user 0m0.948s sys 0m0.004s $ du -hs systemd_210.orig.tar.xz 3,8M systemd_210.orig.tar.xz gzip === $ time gzip systemd_210.orig.tar real 0m0.590s user 0m0.580s sys 0m0.012s $ du -hs systemd_210.orig.tar.gz 4,1M systemd_210.orig.tar.gz lz4 == $ time lz4 systemd_210.orig.tar Compressed filename will be : systemd_210.orig.tar.lz4 Compressed 28917760 bytes into 6667707 bytes ==> 23.06% real 0m0.097s user 0m0.080s sys 0m0.012s $ du -hs systemd_210.orig.tar.lz4 6,4M systemd_210.orig.tar.lz4 -- Why is it that all of the instruments seeking intelligent life in the universe are pointed away from Earth? _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel