[gentoo-amd64] Re: 64 bit or not

[Duncan]

Harry Putnam posted <ubqzt9dzh.fsf@×××××××.com>, excerpted below,  on Wed,
07 Dec 2005 08:30:10 -0600:

> I'm about to install gentoo on an athlon64.  Is there enough 64 bit
> software and other good reasons to use the 64 bit version?
>
> Although a long time linux user, I'm not particularly skilled at dealing
> with problems (a slow learning or just thick headed I guess).
>
> But have cross posted this to hear from both 32 and 64 bit advocates.

Thanks for mentioning the cross-posting.  Few enough have the courtesy to
do so.

For the most part, the Free, Libre, and Open Source Software (FLOSS) side,
certainly for the commonly used stuff, has long ago been ported, and will
present little or no issues related to 64-bit.

The problems, where they exist, therefore almost all relate to closed
source unfree software that cannot be ported by the community.  Even in
these cases, however, AMD64 is actually a dual-bitness arch, and can run
32-bit software even on a normal 64-bit system, provided support is
activated in the kernel, and a multilib profile (the default amd64
profiles) is chosen.  It does get a bit more complicated, but it's not
overly so, and there is plenty of documentation and help available when
needed.

Basically, there are four applications areas and two kernel areas one
needs to worry about, all proprietary only, games, multimedia codecs,
open office, and browser plugins, on the userland side, video and network
drivers, depending of course on your hardware, on the kernel side.

The easiest way to solve the userland side is to merge the 32-bit
binary-only compatibility libs (glibc, gcc, and portage's sandbox, are
exceptions that are normally compiled with support for both bitnesses). 
This will support most 32-bit-only binary-only games, as well as the
32-bit binary-only compatibility ebuilds for firefox, mplayer, and open
office.  Note that 64-bit versions of mplayer and firefox can be compiled
from source as is usual for Gentoo, but because 32-bit libraries won't
function in 64-bit apps, and certain codecs (the windows media stuff, for
example) and plugins (flash, for example) are only available as
proprietary binary-only 32-bit libs, those will be unavailable to the
64-bit versions of firefox and mplayer.  Whether that's a problem for you
depends entirely on how much you depend on unfree software. 
OpenOffice.org isn't yet fully 64-bit ported, tho that is expected for the
2.1 version.  However, due to its size, even many 32-bit Gentoo users run
the binary version of it.

The kernel side is similar.  Some network drivers, particularly wireless,
are only available in proprietary 32-bit kernel modules (or require the
bridge, I forget it's name, allowing 32-bit MSWormOS drivers to be used
under Linux).  That can be a major issue, but it's easily solved if one is
willing to either do the research and buy only open source supported
hardware originally, or fork over the money to switch NICs to a supported
one, later.

Both ATI and NVidia now have 64-bit proprietary modules that can be
inserted into the kernel.  This is of course only required for 3D support,
the most common use of which is unfree games, so if you don't use
unfree software, it's not so much of an issue.  NVidia support tends to be
better, but it's still proprietary. Again, the problem is easily solved if
one does the research and buys something with open source drivers, such as
ATI Radeons thru the 9250, but not later with 3D support, tho 2D support
works. (Xorg 7.0, just now coming out, is said to include experimental
3D support for newer ATI cards, but it's just that, experimental, and they
had to reverse engineer the cards to get it, because ATI quit cooperating
with the open source community after the 9250.)

Here, I choose not to run what I call slaveryware, because it's not free
(see my sig), so I don't have to worry about closed source 32-bit-only. I
run a Radeon 9250 with the open xorg native drivers, and did the research
on my motherboard to know everything on it, including the network chip,
had in-kernel Linux drivers available. I don't need Open Office, so that
doesn't bother me either.  I have been running the default multilib
profile, but since I don't run any 32-bit apps (save for booting with
grub, which also has a 32-bit binary compatibility package in portage,
grub-static) and compiling the 32-bit support into gcc and glibc in
particular takes additional merging time, I'm currently considering
switching to the no-multilib profile.

Condensing that all down to a simple summary, most stuff you will run is
available in 64-bit, no problem.  The problems, with the exception of
OOo, are mainly confined to 32-bit-only proprietaryware, but even then,
32-bit runs quite well on the amd64 arch.  Setting up dual 32 and 64-bit
support is a bit more complex than 32-bit only, but there's the usual
level of good Gentoo documentation and help available when it's necessary,
so most run it with very little more difficulty than they'd have running
32-bit x86 Gentoo.

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman in
http://www.linuxdevcenter.com/pub/a/linux/2004/12/22/rms_interview.html


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