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Woodsman 04-25-2014 12:29 AM

Selecting 32-bit vs. 64-bit OS guidelines
 
I am looking for general hardware guidelines, rules of thumb, or a decision flow chart when to install 32-bit or 64-bit operating systems.

Obviously the CPU is a starting point, but what else plays a role in the decision? For example, when 1 GB RAM is installed (or even 512 MB?), would a 32-bit OS be better even with a 64-bit CPU installed? (That might be an unrealistic example but that is the kind of inofrmation I am seeking.) What about the video processor? Etc. Or is the CPU really the only criteria? Sort of like minimum/recommended hardware requirements, but not exactly.

Edit: I probably should add, are there are any "gut check" tests that can be run with either OS after booting into the desktop to gauge whether a system is performing reasonably?

Thanks. :)

allend 04-25-2014 12:42 AM

Some finer technical points were presented in this recent thread. http://www.linuxquestions.org/questi...er-4175502202/

My general rule of thumb would be install a 64bit operating system if the CPU supports it and there are no software limitations.

TracyTiger 04-25-2014 12:49 AM

RAM
 
One minor point to consider is that it may be easy to increase RAM in the future without causing any other work.

For example say that 32bit was chosen instead of 64bit only because there was less than 4GB of RAM. And if there had been more than 4GB of RAM then 64bit would have been chosen. If a future increase in RAM (say to 6GB) is a real possibility then it is simple to increase the RAM and not touch the software if 64bit had been installed originally.

This is probably at the bottom of the list of things to consider.

Woodsman 04-25-2014 01:10 AM

Quote:

My general rule of thumb would be install a 64bit operating system if the CPU supports it and there are no software limitations.
So if you have an unrealistic combination of a 64-bit CPU and 512 MB RAM you would install a 64-bit OS?

Quote:

One minor point to consider is that it may be easy to increase RAM in the future without causing any other work.
I agree, but I am presuming in this discussion there will be no future expansion of the hardware.

I am looking at this from the perspective that somebody asks me to install a Linux system on their computer and they can't afford hardware improvements, which is one reason they want to install a Linux system. There are many variables such as choice of desktop environment, but I am trying to find some general guidelines as to which OS to start with. My approach is I get only one chance to make a first impression.

TracyTiger 04-25-2014 01:22 AM

Quote:

I am looking for general hardware guidelines, rules of thumb, or a decision flow chart when to install 32-bit or 64-bit operating systems.
Quote:

There are many variables such as choice of desktop environment, but I am trying to find some general guidelines as to which OS to start with. My approach is I get only one chance to make a first impression.
Although you specified hardware guidelines, perhaps in the end, software is the only thing that needs consideration in the 32bit vs 64bit decision.

EDIT: Assuming of course a 64-bit CPU. :) As you suggested there may be some low RAM extremes where the system would use up too much precious RAM if 64-bit was used instead of 32-bit.

ReaperX7 04-25-2014 02:21 AM

My synopsis...

Use what your CPU supports. If you have an older x86 processor go with 32-bit, if you have an AMD64/EM64T then go 64-bit and/or multilib.

Smokey_justme 04-25-2014 04:20 AM

Quote:

Originally Posted by Woodsman (Post 5158804)
So if you have an unrealistic combination of a 64-bit CPU and 512 MB RAM you would install a 64-bit OS?

No.. A 64-bit OS will consume a bit more memory (or at least that's my impression -- never quite researched this) and 512 RAM is quite limiting this days.. But that's just what I would choose..

PrinceCruise 04-25-2014 06:18 AM

Installing 64 Bit OS on a 512MB RAM machine is killing it IMHO. Heck, I installed 64 Bit Windows 7 on the 1GB Netbook I have and it screwed up the basic tasks like opening Chrome and watching videos. Had to install 32 Bit on this to make it bit usable.

I understand the sentiments behind use what your CPU supports but RAM is a big factor which can't be ignored.

Regards.

enine 04-25-2014 07:27 AM

I ran into this situation. I use old laptops for things so I can pass them down to my kids to use as I get newer ones, usually the laptop I use becomes my server/lab then goes to one of my kids. I was running a 32bit Slackware on 32bit hardware with 2G ram and could run 3-4 virtual guests. But some newer OS's are 64 bit only so I found a used laptop cheap that had a 64 bit CPU, installed Slackware 64 and can barely run one virtual guest in 2G of ram. Laptops are usually limited in the amount of ram they can support so I can't easily upgrade to 6 or 8G so I am in the process of installing the 32bit Slackware now.

tronayne 04-25-2014 09:11 AM

Things I'm leery of when looking for a new box (they're pretty much all 64-bit now, hard to find a 32-bit) is the RAM (8G minimum, 16G better).

The things I think about are manufacturer. I like Dell -- I don't have problems with them and they last for years. I order direct from Dell and get the box configured the way I want it.

I don't want terabyte drives -- with all the crap I've done for decades I have never, ever gotten anywhere close to even 500G. I want reliability (my servers are never turned off except when the power goes out and the UPS battery goes flat or I have to add some hardware (like a Blue-ray burner). I have had bad experience with disk drives (I keep spares on the shelf) and I just don't trust that a terabyte drive is going to last. Just me, been burned over the years.

I don't want fancy-schmancy graphic cards. I'm perfectly happy with stock Intel graphics, don't want to deal with proprietary driver software (been there, did that, didn't like it very much). I don't play games on computers (well, Spider solitaire when I'm bored or waiting for something). I have a new HP 23xi IPS LED monitor, sharp as at tack, shows Blue-ray movies just fine with the Intel graphics.

With the exception of two Dell Dimension 8400s, that date from 2005, everything is 64-bit. The Dimensions are headless data base servers, one MySQL/MariaDB, the other PostgreSQL. They have 4G RAM, they sit in a closet mumbling to themselves and, other than a bad capacitor in one them (a new motherboard was $60), no problems.

Would I buy another 32-bitter? Nope. Those Dimension fail, they'll get replaced with 64-bit (with, like, 16G RAM and probably a quad core processor). They're not pig-dogs, but they are slow compared to everything else.

The machine I'm working on is a Dell Optiplex 780. Dual core, 8G, 250G drive. Does everything I ask of it (a lot of geographic projections and analysis along with everyday reading, writing and arithmetic). No problems, it's quick, it's clean and it works. On this box I have Win7 in VirtualBox, no problems there... well, it is Windows and it blows, but it works when I have to hold my nose and boot it.

I have not bothered with multilib, I've just accepted that there are applications that are 32-bit and probably won't be upgraded to 64-bit (like Adobe Reader). Okular is not Adobe Reader but it works, good enough.

I don't ever fiddle with the kernel, I don't fine-tune anything. I install patches as they become available. I value stability above, pretty much, all else. Slackware has been the only Linux distribution I have ever used (a couple of brief, real brief, forays into the world of *buntu for about a day in VirtualBox). I can't find any reason to use anything else. When I buy and install for a customer, it's Dell, Samsung or HP LED monitor, Zero keyboard, HP printer, Linksys router, APC UPS. Enough processor and RAM to do what needs doing (Intel Xeon quad core and 8- to 16G RAM), one or more 500G drives.

And Slackware -- I don't like phone calls at 0300.

I used to be impressed, during a wasted youth, with the bells and whistles -- I'd rather have a Jeep than a Ferrari.

But, back the basic question, if you've got a client that has a reasonable 32-bit platform, install Slackware on it and let it live out its life. When it dies, replace it with a 64-bit box and everybody's happy.

Hope this helps some.

hitest 04-25-2014 09:21 AM

Yes. A 64 bit install does use a bit more RAM than a 32 bit install of Slackware. If the box can support it I would go 64 bit unless you need specific software(multilib).

metaschima 04-25-2014 12:22 PM

My rule of thumb is always install 64-bit unless the machine is 32-bit or unless you need and cannot run it via multilib or find and replace a 32-bit only program. So, in almost all cases 64-bit is the way to go.

jtsn 04-25-2014 12:58 PM

Quote:

Originally Posted by Woodsman (Post 5158784)
I am looking for general hardware guidelines, rules of thumb, or a decision flow chart when to install 32-bit or 64-bit operating systems.

Rule of thumb for Linux on x86: Below 896 MB RAM you go with 32 bit, above 896 MB you go with a 64 bit kernel, above 2048 MB you go with a 64 bit userland and multilib.

Woodsman 04-25-2014 01:13 PM

Hmm. Nothing definite yet offered here. :)

At one end of the spectrum is a 32-bit CPU: no choice at all, just install a 32-bit OS. At the other end of the spectrum is a 64-bit CPU with 4GB or more RAM: install a 64-bit OS. In between is a gray area.

I am not concerned about things like PAE. I am concerned with how the user will respond to the newly installed system. I need to support people with a wide variety of hardware. Thus I want to provide myself some guidelines. I get only one chance to make a first impression.

Many people buy systems with 1 or 2GB of RAM with a 32-bit OS pre-installed. They survive happily because they never push the hardware. They surf the web and check email and little more.

These people are running XP and are migrating to Linux. I have no idea what CPUs or amount of RAM they have --- until I get my hands on their box. These are people who do not push their hardware. Yet from their perspective, their new system has to run as fast or faster than what they saw with XP.

A safe approach might be to just install a 32-bit OS and move on.

I have no benchmarks or guidelines about that gray area. Classic system benchmarks are of no help. I need "gut check" benchmarks. Not "geek check" benchmarks but everyday user benchmarks. I don't have a slew of old hardware to run my own "gut check" benchmark experiments.

I have spent much time surfing the web trying to find some guidelines. I have not been successful. The best I can speculate is to use 2GB RAM as a starting point rather than the CPU. Anything with 2GB or less then install a 32-bit OS regardless of the CPU.

There are possible corner cases, such users one day splurging to buy more RAM. They then would be stuck with a 32-bit OS rather than 64-bit OS. I do not foresee that happening often. Many of these people are migrating because of budget issues, such as fixed incomes.

Yet even if a user splurged on more RAM, everything I have read indicates most users with nominal usage of a computer never notice any difference between a 32-bit and 64-bit OS. They don't push hardware and they are not developers or number-crunchers. So perhaps my speculative 2GB RAM starting point is good enough. I just wish I had more confidence in my speculation. :)

Quote:

Rule of thumb for Linux on x86: Below 896 MB RAM you go with 32 bit, above 896 MB you go with a 64 bit kernel, above 2048 MB you go with a 64 bit userland and multilib.
Oops, I saw this after I posted. Are you able to share from where you derived this rule of thumb? Your thinking is similar to what I posted above. That is, based on RAM rather than CPU.

tronayne 04-25-2014 02:02 PM

You probably already know that many (if not most) XP boxes are pretty limited in the RAM area, maybe 512M, maybe 1G, but, pretty darned rare that they'll have 2G or better (up to 4G).

RAM's cheap. MicroCenter sells RAM strips (1G, 2G and 4G) for, well, not a heckuva lot (like $20 up to about $60 or less). That really should not be a huge burden on somebody (at least I haven't found it to be when I've done those systems for folks); that's also with the understanding that sometimes it is burden (I keep a stock of removed RAM strips so I can donate the removed-from-service parts and get 'em going).

You'll probably have enough disk drive (if the thing is still good) and eBay can be your friend for certain old types of RAM and even drives (they're probably not going to be SATA).

When I do these upgrades on an XP box, I check the thing for what's in it, tell the client that we need to increase RAM to at least 1G or go all the way to 4G. Most accept that there is cost involved and the secret words ("It'll be faster") seem to work wonders, too.

If you're going to put Slackware on them, it does have a relatively small footprint, especially if you use Xfce rather than KDE.

On the other hand, if it's 64-bit box, install 64-bit Slackware and be done with it; up the RAM if it's lacking, but don't bother putting 32-bit Slackware on a 64-bit platform (it'll work but you're stuck).

You know you're going to have to spend some time teaching, might as well do that with Xfce, eh?

Hope this helps some.

Woodsman 04-25-2014 05:35 PM

Quote:

You probably already know that many (if not most) XP boxes are pretty limited in the RAM area, maybe 512M, maybe 1G, but, pretty darned rare that they'll have 2G or better (up to 4G).
I have decided that if they have less than 1 GB, end of discussion, and install 32-bit.

The area between 1GB and 2GB remains gray to me. For now I am going to use 2GB RAM as my starting point. If the customer has 2GB or less then that person is not a power user. And I can tell quickly from the first conversation the level of their computer skills. Thus installing a 32-bit OS is fine and they will never notice the difference. Nor will they care or want to learn the difference. In time I hope I can develop a better feel for the decision point about whether to install 32-bit or 64-bit.

Quote:

That really should not be a huge burden on somebody (at least I haven't found it to be when I've done those systems for folks); that's also with the understanding that sometimes it is burden
I will keep that in mind. These folks have already accepted there is a cost to having somebody update their system. They are not tech savvy and the opposite is more true --- that they are tech phobic. Not Luddites, just phobic. Ye their lack of computer skills places them in a position to depend upon somebody else to help them.

I need to temper the final cost with pragmatism. These folks are not geeks. Adding RAM is not something they really understand, even if I tell them the system will be faster. Their perception of speed begins with the desktop.

Right now I have a customer box in my office that is 10+ years old. I suspect the box is a 32-bit CPU and if so then case closed for that specific system. If the system contains an older single core 64-bit CPU, then I have the weekend to run some "gut check" benchmarks. I also have the demo system for the store-front that has a single core 64-bit CPU and 2GB RAM. I have the weekend to run some "gut checks" with that too.

Interestingly, I learned a lot with today's customer. They are retired, do nothing more than surf the web and check email through an online mail account. When I started the browser on the demo machine and the browser did not open the home page to what they are familiar, I could tell they were straining their minds a bit. So I changed the home page to their preference, restarted the browser, and their faces lit up like the proverbial light bulbs. They asked me to copy some photo images from their XP system to a CD, that is the limits of their computer skill set. Today's observations tie into my other thread about Slackware GUI admin tools where I shared that these types of users think differently than us geeks. Watching them use the demo computer opened my eyes to this other end of the user spectrum.

Quote:

You know you're going to have to spend some time teaching, might as well do that with Xfce, eh?
Yes, and the installation fee includes two hours of tech support. I can't do everything from the bench when I install a Linux system and some things will have to wait for when they return home with their box. For example, connecting their printer. For these users I will write a pamphlet for connecting printers. Or deliver the box to their home and perform the connection myself. Fortunately for me, this customer has an HP printer rather than a printer from one of the vendors that don't support Linux.

We geeks take so much for granted. In an odd way, I am going to enjoy this venture in meeting people who are not geeks and learning how they use and think about computers.

We are going to support Cinnamon, Mate, and possibly Xfce. Most of the customers will not choose or even be informed of the multiple desktop choices available with a Linux system. That would be information overload. We will choose the desktop for them based upon hardware specs. That is one reason I started this thread. Xfce will more or less be a desktop environment of last resort for those folks with severely limited hardware where even Mate sputters. I expect mostly to install Cinnamon and Mate.

tronayne 04-26-2014 08:36 AM

I thing you've got it just about right. Basic good sense tells you that anyone still running XP is... well, not a geek (if there actually is such a thing as a Windows geek). The folks I've worked with have needed some hand-holding and little TLC to get going but, you know what? Half an hour of TLC and you get calls from folks that need some help (read: new customer! That nice young man helped me, why don't you call him? Cripes, I just turned 70 and I may be nice but I sure as hell ain't young).

Gram wants e-mail, pictures of the grandkids, maybe a little (or a lot) of Facebook (and Facebook games, too, be careful there), maybe a little shopping at Macy's, maybe a little shopping for places to stay on a trip. Maybe some YouTube videos of the kids. Not a whole let else.

If you've ever dealt with users, either as an administrator or as a developer, you know what I mean -- they really don't want to know, they just want the damned thing to work.

I'm still of the opinion that you can't be too rich or too thin -- the more RAM the happier the client. It's a little extra that goes a long way toward a happy camper. I also think that if it's a 64-bit box, keep it a 64-bit box (and vice versa). More RAM, less trouble. But that's just me and I've got clients that are happily using using dial-up (for $6 a month) so there you go.

Best of luck!

jtsn 04-26-2014 09:11 AM

Quote:

Originally Posted by Woodsman (Post 5159128)
Oops, I saw this after I posted. Are you able to share from where you derived this rule of thumb? Your thinking is similar to what I posted above. That is, based on RAM rather than CPU.

Linux memory management becomes slow and inefficient above 896 MB RAM on IA32. So on the kernel side you switch to a 64 bit kernel above 896 MB RAM.

Userland is a different story. A 64 bit userland requires more memory than a 32 bit userland, so you should not install it on systems with less than 2 GB RAM. That of course heavily depends on what you use as your userland.

The often mentioned 4 GB limit has different reasons and nothing to do with x86-64 support: A 32 bit x86 Linux kernel compiled for 64 GB RAM just doesn't boot on old CPU models, so you need a different kernel for these, which is limited to 4 GB, not because of 32 bit, but because it has to support these old CPUs (down to 486), which were constrained to 4 GB physical RAM.

enine 04-26-2014 07:00 PM

2G seems to be a good cut over. My 2G laptop going from 64 bit to 32 bit was night and day difference in performance.


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