On Fri, Jul 20, 2007 at 05:50:20PM -0700, Chuck Swiger wrote: > On Jul 20, 2007, at 5:37 PM, Norberto Meijome wrote: >>> Is it normal for bzip2 to be significantly slower than gzip? >>> If not, where can I look for things that might be causing >>> "bzip2 --fast" to take 50-60 times longer to compress a >>> (sendmail log) file than gzip? >> >> i never measured it to see if it is 50-60 times slower, but yes, gzip >> blows >> bzip2 out of the water on speed. I wanted to use bzip2 to compress >> multi-GB >> weblog files, but gzip beat it my miles, and bzip2 wasn't THAT much better >> @ >> compressing it to make it worth it. > > Thanks for the feedback, Norberto. > > Of course, it all depends on what your priorities are, too-- if what you > want is a final tarball which is being mirrored and downloaded frequently, > then your goal is to obtain the absolute best compression, and how much CPU > --best takes isn't important. > > Comparing the default (-5 compression?) of gzip to bzip2 would probably be > more reasonable if you care about reasonably timely compression.
If I read the man page correctly, bzip2 defaults to --best, which is why I compared gzip to bzip2 --fast. With the 1.5G sendmail log, bzip2 --fast compresses to just under 10M in about 55 minutes, give or take. bzip2 --best compresses 1.5G to 1.8M, but takes about 2.25 hours. gzip compresses almost as well (with 3% or so) as --fast, but does it in 1 minute instead of 55 on a dual P-III 1.4GHz (but of course, using only one CPU). Jim _______________________________________________ firstname.lastname@example.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"