Re: CD sizes again (and BoF reminder!)
On Sat, Jul 21, 2012 at 11:42:03AM -0400, Joey Hess wrote:
> Hideki Yamane wrote:
> > On Sun, 8 Jul 2012 17:58:16 +0200
> > Adam Borowski <firstname.lastname@example.org> wrote:
> > > • xz -6 (the default) is a lot slower when compressing, fast when
> > > decompressing, needs only 10MB memory, 58% size
> > > • xz -9 has very slow compression, takes gobs of memory, 56% size
> > > (Obviously, the "size" numbers are dragged down by uncompressible files
> > > when you look at the whole archive.)
> > I tested as well, and sometimes decompression with xz is so sloooow,
> > it takes 6-8 times than default gz.
> I was just watching your DebConf presentation "Lets shrink Debian
> package archive" and I think there you said decompression with xz was
> between 2x and 6x slower. Is that the current number?
> I'm concerned with the thought that installation of Debian (as well
> as debootstrap) could take twice or more as long if xz were used for
> say, every package on a Gnome desktop CD. In d-i we try to make
> installation faster; slow installs make people less happy. It would
> be useful to have some real-world installation time benchmarks with
> and without xz.
Note that slower decompression doesn't necessarily mean longer
installation time. I/O is still more time consuming than CPU.