Re: Future releases as tar.bz2 and tar.xz

[Christopher Roy Bratusek <zanghar freenet de>]

Am Mon, 18 Jan 2010 11:21:17 +1100
schrieb Allan Duncan <amd2345 fastmail com au>:

> On 18/01/10 07:59, Christopher Roy Bratusek wrote:
> > Hi all,
> >
> > nothing special, just some news:
> >
> > all future releases will be available as tar.bz2 and tar.xz.
> > XZ is also known as LZMA2 and has a much better compression than
> > bz2.
> >
> > For example Sawfish 1.6.1:
> >
> > du -h sawfish-1.6.1.tar.{xz,bz2}
> > 2,4M sawfish-1.6.1.tar.xz
> > 3,6M sawfish-1.6.1.tar.bz2
> >
> > So this is -30%, which helps saving bandwith and stuff. Though not
> > necessary for most people, but in non-industrial countries (or in
> > non-urban regions) there are a lot people who can't access DSL (and
> > flatrates).
> >
> > Chris
> >
> 
> Of course the compression comes at a cost - it really chews CPU time.
> For those using GNU tar, the man page is less than helpful, use:
>      tar --xz -cf <archive.tar.xz> <source>
> If there is an abbreviated option I can't see it.
> Extraction/listing
>      tar -xf <archive.tar.xz>
>      tar -tf <archive.tar.xz>

compression (sawfish 1.6.1)

bzip2 -9: CPU 90% max. 5,477 seconds 3,6M size
xz -9: CPU 98% max. 9,414 secons, 2,4M size

decompression (sawfish 1.6.1)

tar xf (bzip2): CPU 74% max. 1,116 seconds
tar xf (xz): CPU 14% max. 0,573 seconds

Well the compression time and CPU usage doesn't matter here, as I got a
Quadcore AMD Phenom. The decompression time and CPU usage from XZ is
far better than BZip2, obviously.

Chris