Re: Upcoming Debian multiarch support (amd64, sparc64, s390x, mips64) [affects sarge slightly]

[Colin Watson <cjwatson@debian.org>]

On Mon, Jan 12, 2004 at 10:47:22AM -0500, Anthony DeRobertis wrote:
> On Jan 11, 2004, at 15:16, Scott James Remnant wrote:
> >Or just have separately named packages?  With the "lesser ABI" package
> >depending on the "major ABI" one as I outlined in my other e-mail.
> 
> AMD Opteron processors apparently run faster in 64-bit mode, due to 
> having more registers available. Having one of those systems, I'm sure 
> that 64-bit is the "major ABI" --- I don't really see much reason to 
> keep 32-bit around if I don't have to.

It's not necessarily that simple; many applications are disk-bound
anyway, and furthermore in 64-bit mode you spend more time shuffling
pointers around. When I was doing benchmarking work on the Opteron at
AMD early last year (albeit on web servers, so perhaps not a good
analogy for desktops), it was becoming clear to me that having the
flexibility of 32-bit mode for some applications and 64-bit for others
was useful, and the results of some of those benchmarks were slightly in
favour of 32-bit mode.

I haven't touched an Opteron for nearly a year now, though ...

-- 
Colin Watson                                  [cjwatson@flatline.org.uk]