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-   -   Slackware 64 or 32 bits on AMD Turion 64 X 2 ? (http://www.linuxquestions.org/questions/slackware-14/slackware-64-or-32-bits-on-amd-turion-64-x-2-a-4175460260/)

fredak 05-01-2013 04:24 AM

Slackware 64 or 32 bits on AMD Turion 64 X 2 ?
 
hello
I've been working in the IT since 20 years and I have always use unix, first at the university and then at work. I am a basic user, I know the commands, how to write shells, etc, but I never had to install, configure etc. Since a few weeks I've decided to put Linux on my home computer and get rid of windows and I am now dealing with all the installations and configurating issues. In french we say "petit petit l'oiseau fait son nid" which means literally "little by little, the bird makes its nest", that what's what it is happening to me right now.

Let's get to the point : a friend of mine suggested I should install Slackware 14.0 32 bits. he told me since I have only 1 Gb RAM I shouldn't put a 64 bits OS.

But still, since the sticker on my labtop says : "AMD Turion 64 X 2" which means I guess that I have a double core 64bits processor, I am really wondering :

should I install the 64 bits OS ?

Martinus2u 05-01-2013 05:23 AM

First observation: it is main memory plus swap space you need to consider, as the 64 bit question is about the virtual process address space more than the physical memory. However, if you use large amounts of swap you won't be happy with the machine, I promise.

Second observation: a 32 bit kernel can address around 896 MB physical RAM unless large memory support is enabled (which would be the case in the Slackware stock kernel)

Third observation: 64 bit applications can use more and longer registers, but pointer variables are longer. Still, most applications perform a little bit better in 64 bit.

So maybe the best advice is: if you can upgrade the memory, do it, and go 64 bit. Otherwise stay with 32 bit.

digger95 05-01-2013 05:50 AM

Which windows version were you running and how did it perform with 1GB of RAM?

digger95 05-01-2013 08:06 AM

I've had both versions of Slackware 14 on my low-end machine (Sempron 140 + 3GB RAM) and to be honest I haven't really noticed much of a difference between the two. If I were to reinstall today I'd just stick with the 32-bit version and that way I wouldn't have to deal with the whole multilib business. Yeah, I know I'm lazy. :)

allend 05-01-2013 09:36 AM

I run both Slackware 32bit and Slackware 64bit on a machine with 1GB RAM. I think the 64bit version boots a bit faster (but have never actually measured it). In general operation, there is no noticeable difference. The only issue I have had with running 64bit is with my printer; the driver is 32 bit only, so I need to add the glibc-solibs-2.17_multilib-x86_64-2alien.txz and cups-compat32-1.5.4-x86_64-2compat32.txz packages from http://taper.alienbase.nl/mirrors/pe...lien/multilib/ to use the printer in Slackware 64bit.
It really comes down to the software that you want to run. There are some programs, e.g. Skype, that are only available in 32bit versions. I also use one program that is only available in a 64bit version. Some calculation intensive programs seem to run a bit faster in 64bit.

273 05-01-2013 09:40 AM

Quote:

Originally Posted by Martinus2u (Post 4942497)
Second observation: a 32 bit kernel can address around 896 MB physical RAM unless large memory support is enabled (which would be the case in the Slackware stock kernel)

Are you sure? I was under the impression it was about 3.8GB?

onebuck 05-01-2013 10:15 AM

Member Response
 
Hi,

Welcome to LQ!

Quote:

Originally Posted by fredak (Post 4942467)
hello
I've been working in the IT since 20 years and I have always use unix, first at the university and then at work. I am a basic user, I know the commands, how to write shells, etc, but I never had to install, configure etc. Since a few weeks I've decided to put Linux on my home computer and get rid of windows and I am now dealing with all the installations and configurating issues. In french we say "petit petit l'oiseau fait son nid" which means literally "little by little, the bird makes its nest", that what's what it is happening to me right now.

Let's get to the point : a friend of mine suggested I should install Slackware 14.0 32 bits. he told me since I have only 1 Gb RAM I shouldn't put a 64 bits OS.

But still, since the sticker on my labtop says : "AMD Turion 64 X 2" which means I guess that I have a double core 64bits processor, I am really wondering :

should I install the 64 bits OS ?

Personally I use both x86_32 & x86_64 on similar hardware. I do not use multilib on older 64 machines. You could do a install for 32 & 64 on the machine or use 64 with multilib. I keep my installs vanilla except when I need a special bench setup.

Look at Slackware Doc Project & for Configure your new Slackware System to aid you.

Hope this helps!

chrisretusn 05-01-2013 10:29 AM

If it was me... I'd install Slackware64 simply because it's a 64-bit capable machine. The machine I typing on right now is an "Intel Centrino Dual Core" with Slackware64-current. I do have a bit more memory that 1GB though, 3GB. That said, I'd still install Slackware64, even with only 1GB.

H_TeXMeX_H 05-01-2013 11:00 AM

I think you can safely install slackware64, and if you need 32-bit software, just use multilib. It's true that installing slackware32 will probably be less of a hassle. It's your choice. Overall I think there will be a performance benefit if you use 64-bit.

narz 05-01-2013 03:55 PM

Quote:

Originally Posted by 273 (Post 4942659)
Are you sure? I was under the impression it was about 3.8GB?

I think maybe only the kernel itself addresses 896 MB but I don't even get how that's how relevant to userland operation.

storkus 05-01-2013 09:22 PM

Having this exact same processor myself (in my el-cheapo Wal-Mart post-Christmas Acer laptop special from 4 years ago or so), I think I can add a bit here: being AMD, it is 64 bit native with 32 bit emulation (in microcode?) so for basic tasks you won't see much of a difference. You WILL see a small, but noticable difference in high end tasks like games, booting up, and so on: I personally notice the biggest difference with my NVIDIA IGP, which definitely seems to prefer being fed natively 64 bit (bigger registers?).

Also remember that with Slackware, you can go multi-library with Eric's (Alien Bob) multi-lib packages; I leave it to you to determine if it's worth the effort.

The catch with going 64 bit is some native 32 bit apps (especially Wine) and code that is physically larger, thus needing more memory and possibly resulting in more cache misses (AMD desktop/mobile procs have tiny caches). My machine came with 2GB of RAM and I have never needed to expand it (only the GIMP has ever maxxed it out). In use it usually hangs out around 500-600 MB, but then again I'm running Xfce, not KDE. YMMV.

My advice: if you've been using it and not maxxing out your RAM, then why invest another penny? If you are hitting it, you need to decide if upgrading the RAM is more worthwhile than buying a new machine. Remember that the Turion X2 is around 5 years old now, and while ok for office stuff and light graphics, is not sufficient for major gaming (although this is more determined by your GPU, which is probably an IGP if you have this processor); it's also not terribly power efficient.

One last thing if you are thinking about new hardware: work is ongoing to get Armed Slack aka Slackware-ARM to work on the ARM Chromebook--for non-gaming stuff this could be huge with amazing battery life that can't be had on the PC (WIntel) architecture. See here:http://alien.slackbook.org/blog/armport

Hope this helps, Mike

Erik_FL 05-01-2013 10:37 PM

It won't make a lot of difference in performance whether you use a 32-bit kernel or a 64-bit kernel. The 64-bit software may be slightly faster because the 64-bit execution has probably been optimized in the CPU. The 64-bit software will also be slightly larger, though it isn't twice as big. There are only a few situations where addresses and data with small values absolutely have to be stored as 64 bits.

With 1GB of physical RAM I recommend using a 32-bit kernel. The programs will be slightly smaller, and you won't have two copies of libraries loaded when running a 32-bit program (and a 64-bit program). KDE uses a lot of RAM. The 64-bit version of KDE will use a little bit more than the 32-bit version.

With a 32-bit kernel, a single process (task) can directly access up to 3GB of memory. Very few programs need to directly access more than 3GB of RAM. A process uses the other 1GB to access software and data in the kernel. A process can also re-map the 3GB of addressing to access more than 3GB of physical RAM.

The 32-bit Linux kernel can support up to 64GB of physical RAM with PAE (Physical Address Extension). The 64GB is shared between all the processes and the kernel. So, it is not necessary to use a 64-bit kernel to access all the RAM even with more than 4GB. This is different than Windows. Windows 32-bit versions are limited to 4GB of physical RAM because Microsoft never fully implemented support for PAE. Windows only supports the "no execute" bit for PAE, and not the extra four address bits.

You are going to hear a lot of misinformation about 64-bit. Most of the benefit from 64-bit is because of the newer hardware designs and not because of running 64-bit software. Running 64-bit software provides only a slight benefit for most things. Some really well written and optimized 64-bit software may be a lot faster, but that is usually the exception to the rule.

There are a few drivers and programs that still do not support 64-bit Linux. Those are usually older software. So 32-bit has slightly better compatibility with software.

You might want to use a 64-bit kernel because that will eventually be the standard. If your computer is new, you will want to find out about any 64-bit problems now, rather than later. If performance is your main goal, then definitely use 64-bit. Anything that moves large amounts of data around, such as large file copying and graphics will be slightly faster.

273 05-02-2013 03:41 AM

Quote:

Originally Posted by storkus (Post 4943060)
Having this exact same processor myself (in my el-cheapo Wal-Mart post-Christmas Acer laptop special from 4 years ago or so), I think I can add a bit here: being AMD, it is 64 bit native with 32 bit emulation (in microcode?) so for basic tasks you won't see much of a difference.

I don't mean to be picky but it's not technically 32 bit emulation* as the AMD64 instruction set is a superset of i686 -- meaning when you're running a 32 bit OS you are just making use of some of the processor features and half the registers a bit like locking a 4*4 vehicle in rear wheel drive for want of an analogy.


*OK, before anyone points it out the AMD64 and i686 instructions may well be emulated in microcode on the CPU but that's another story.

Martinus2u 05-02-2013 01:05 PM

Quote:

Originally Posted by 273 (Post 4942659)
Are you sure? I was under the impression it was about 3.8GB?

I am. Reason being that linux implements the unix principle of the monolithic block, meaning the kernel address space is part of the address space of every running process (even though the access is protected by the MMU). Without high mem support the kernel maps the entire physical memory into the kernel address space. Oh, and the standard split of the 4GB process address space is 3 GB user, 1 GB kernel.

Your statement about 3.8GB or thereabouts (depending on the hardware) is correct once you enable high mem support (without PAE which enables up to 64 GB).

273 05-02-2013 01:21 PM

Ah, yes, I forgot about the 1:3 split.


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