Reverting to 32-bit -- looking for tips

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AllTom · Post by **AllTom** » Tue May 25, 2004 1:32 am

I thought that I was up to the task, but I'm not. Running 64-bit Linux has tested my patience in several areas:

Not only am I waiting for 64-bit drivers for my Radeon 9800 Pro, but I haven't even been able to get 2-D acceleration to work (which is supposed to be built-into XOrg, right?)
Segmentation faults in several applications that I used to use, memory leaks in applications with supposed 64-bit support
Chrooting --- I made one, ran a few trivial 32-bit binaries, but missing library errors were rampant with larger applications and many just refused to run

I'm a Linux enthusiast (you know, read the manual, play with configurations, pull CVS nightlies), but trying to run my system with 64-bit everything has gotten on my nerves. I borrowed a Pentium III laptop the other day and everything just worked. I came home and reminded myself of all the software I couldn't use and all the binaries that wouldn't run and I would have stupidly installed Fedora if the installer (bless its soul) crashed when it tried initializing video drivers --- I only had the x86 version handy.

So anyway, I want to know how feasible it would be for me to retreat to my 32-bit world where my portage overlay isn't full of hacked ebuilds to include the amd64 keyword. If I were to do this, which considerations should I make?

Would drivers for things such as my gigabit LAN device and video card work? (I have the Asus K8V Deluxe motherboard, by the way)
Would the system actually work?
Is there a non-destructive way to do this and keep everything in / ?
Would such a transition actually improve my situation or would I be plagued with new incompatibility conundrums with even less documentation?

I've browsed on these forums enough to know that there are more than a few people weird enough to try something like this. What's the story? Can I be the easy-going emerge junkie I used to be?

chizu · Post by **chizu** » Tue May 25, 2004 2:53 am

Yeah, Gentoo-amd64 still has a long way to go. I tried it a few days ago and found myself unable to get gcc working. But anyways, I was in the situation you described just a few days ago and switching over to x86 worked really well. Just run everything as though you were using an Athlon-XP and it works perfectly.

1) Drivers work better.
2) Yeah, very well.
3) I'm not sure, there might be, but I would strongly suggest reinstalling.
4) Yes, it will improve your situation a lot. There will be some incompatibility but it will be extremely minimal compared to what you have now.

Good luck!

Sivar · Post by **Sivar** » Tue May 25, 2004 3:13 am

I've been thinking of doing this on my laptop as well. The MADWIFI (Atheros wifi) driver does not even pretend to work in 64-bit land, making Linux on the laptop fairly useless unless there's an RJ45 handy. DVD playback has been incredibly flaky. Many important apps are masked or stay masked longer than their 32-bit counterparts. I wish AMD would provide Opteron systems for Gentoo's key developers.

Almost every executable program would need to be completely replaced, so I would definitely back up important data and just do a complete reinstall.

Perhaps in a few years when AMD64 operating systems have matured...

AllTom · Post by **AllTom** » Tue May 25, 2004 11:43 am

Thank you both very much for the information. Tonight or tomorrow (or the day after, knowing me

), I'll start the process of converting. I plan on backing up everything in the /etc directory for reference, my Apache configurations, and my world file so I can remember which applications I had installed. I'm glad to know that I can again use a 32-bit kernel and software on this machine.

Thanks again.

ernstp · Post by **ernstp** » Tue May 25, 2004 1:13 pm

I have gentoo on two partions, one x86 and one amd64.
X86 for normal use, with Realplayer, Flash, ATI drivers etc. and amd64 for testing. But hey, my amd64 install works great, 2D accelleration, gcc 3.4, gnome 2.6.

SiggiS · Post by **SiggiS** » Tue May 25, 2004 4:23 pm

hi,

What CFLAGS do you use to install gentoo-x86 on the Athlon64?

Greetings Marc

blueworm · Post by **blueworm** » Tue May 25, 2004 6:11 pm

SiggiS wrote:hi,

What CFLAGS do you use to install gentoo-x86 on the Athlon64?

Greetings Marc

I use

Code: Select all

CFLAGS="-mcpu=athlon-xp -O3 -pipe"

you can also add msse2 but I haveńt tried I really dont think that all those more exotic CFLAGS are really gonna be that noticable.

did I blaspheme...

naseweis · Post by **naseweis** » Tue May 25, 2004 6:47 pm

Must be your system, somehow.
I'm running 64bit gcc3.4, lots of "masked but working"-apps, mario64 on mupen 32-bit w/o chroot and hell, it's fast!
I'm running an nvidia based card, so my guess would be, you'll be happy, once ATI provides something usable (you get some cheap nvidia card?).
I could solve some of my minor frustrations by adding a bootable 32-bit install, which I made available from 64-bit gentoo by running:

Code: Select all

sudo aterm -tr -sh 40 -fade 70 -g 80x25 -rv +sb -sl 10000 -title "Terminal" -e linux32 chroot /mnt/gentoo32 /bin/bash --login

The sytem need not be bootable, but in your case.....

Here's how:
http://www.gentoo.org/proj/en/base/amd6 ... t=2&chap=4

After some editing in fstab and env.d, almost everything now works like a charm - whatbitsoever.

Good luck! sven

AllTom · Post by **AllTom** » Tue May 25, 2004 7:11 pm

blueworm wrote:
SiggiS wrote:hi,

What CFLAGS do you use to install gentoo-x86 on the Athlon64?

Greetings Marc
I use
Code: Select all
CFLAGS="-mcpu=athlon-xp -O3 -pipe"
you can also add msse2 but I haveńt tried I really dont think that all those more exotic CFLAGS are really gonna be that noticable.
did I blaspheme...

You're happy with these, so I guess that they work well for you. I will use these as well then. (Perhaps -fomit-frame-pointer as well? I used that for both my Pentium 4 and AMD64 installs.)

naseweis wrote:I'm running an nvidia based card, so my guess would be, you'll be happy, once ATI provides something usable (you get some cheap nvidia card?).

My old(er) video card is a GeForce4 MX that was decent, but I wouldn't go back just for Linux when every weekend I game in Windows, which can take advantage of my Radeon.

Hmm.. Is there really a speed difference between running my computer in 32- and 64-bit modes?

SiggiS · Post by **SiggiS** » Wed May 26, 2004 10:24 pm

you can also add msse2 but I have?t tried I really dont think that all those more exotic CFLAGS are really gonna be that noticable.

Which stage2 release do you use (i686 or athlon-XP)? Do you switched to gcc 3.4 on oyur gentoo-x86?

Greetings Marc

blueworm · Post by **blueworm** » Thu May 27, 2004 5:15 am

SiggiS wrote:
you can also add msse2 but I have?t tried I really dont think that all those more exotic CFLAGS are really gonna be that noticable.
Which stage2 release do you use (i686 or athlon-XP)? Do you switched to gcc 3.4 on oyur gentoo-x86?

Greetings Marc

Ehh... neither its the same install I had before upgrading (prevoious CPU and MOBO athlonXP 3000+ asus A7N8X). It was a Gentoo 1.4 rc3 stage1.