Date: Fri, 20 Jul 2007 18:24:55 -0700 From: James Long <list@museum.rain.com> To: Chuck Swiger <cswiger@mac.com> Cc: Norberto Meijome <freebsd@meijome.net>, freebsd-questions@freebsd.org Subject: Re: speed of bzip2 versus gzip Message-ID: <20070721012455.GA5012@ns.umpquanet.com> In-Reply-To: <2BF10D44-4FB5-4F07-B515-553BC705B900@mac.com> References: <20070720220337.GA87174@ns.umpquanet.com> <20070721103710.1e16a319@localhost> <2BF10D44-4FB5-4F07-B515-553BC705B900@mac.com>
next in thread | previous in thread | raw e-mail | index | archive | help
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
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20070721012455.GA5012>