Ubuntu & Debian packages

[John]

Riku Nurkka wrote:

> 
> Yes, I know that the software speed benefits from CPU optimizations are
> often hyped and overestimated... But as nobody's probably even going to
> try to run Ubuntu on an old i486 - not to mention a i386 machine (too
> slow for GNOME etc.) wouldn't it then make even sense to optimize the
> Ubuntu packages for i586, or maybe even i686? 
> 
> It could be a good way to positively differentiate Ubuntu from the
> multitude of other similar Debian-based distros - and quite probably to
> gain much more popularity too.
> 
> One of the main points why many people complain that Debian is too old
> for them is (besides of the relatively slow release cycle & old stable
> packages dilemma) that the official Debian packages are only for i386
> (whether i586/i686 optimization gives a significant speed benefit or
> not) while all the other major distributions have their offcial packages
> compiled (usually) at least for i586. 
> 
> Any thoughts on this?

I have been a Red Hat user for many years, and still take a peek at beta 
time.

I saw discussion on the matter when Mandrake came out with 586 
optimisations. Red Hat's view then was much as Matt says.

It happens RHEL 4 is in beta right now, and I've got a set of unrolled 
ISOs for the desktop version.

There are five 686 rpm.

Two kernels, no surprise there.

One of the several glibc packages (you get to install two or three to 
have the complete glibc).

nptl-devel - threads _developer_ package.
openssl.

That's it.


Everyone does separate kernels; I don't know that it actually makes a 
notcible difference in performance, I sort of expect the most important 
differences are in feature sets, support of hardware paging aids, PAE & 
such.

glibc? Much the same: if 3dNow and SSE make a difference then you 
probably want to use them when available.

ssl? Same deal, encrytption can use serious CPU power, and if the 
hardware can help you want to use it, but otherwise have it not in the 
libraries.

The nptl-devel package comes from glibc source.


RH, I believe, optimises for 686 (Pentium II), but employs the 386 
instruction set. Except for packages specifically designated otherwise.