I have a really silly question... but just want to ask... I have one box on my home network that is x86_64 capable... My other boxes are all i386. As this x86_64 machine can, at most, house 4 GB of RAM (currently only has 1 GB) - is there any advantage to my running x86_64 on that machine instead of i386... Long story as to why I am asking - but before I go off and moveit down to i386 - just wanted some opinions :) Scot P. Floess 27 Lake Royale Louisburg, NC 27549 252-478-8087 (Home) 919-890-8117 (Work) Chief Architect JPlate http://sourceforge.net/projects/jplate Chief Architect JavaPIM http://sourceforge.net/projects/javapim Architect Keros http://sourceforge.net/projects/keros
Scot P. Floess wrote:> I have a really silly question... but just want to ask... > > I have one box on my home network that is x86_64 capable... My other > boxes are all i386. As this x86_64 machine can, at most, house 4 GB of > RAM (currently only has 1 GB) - is there any advantage to my running > x86_64 on that machine instead of i386... Long story as to why I am > asking - but before I go off and moveit down to i386 - just wanted some > opinions :) >on most 64bit capable x86 CPUs, 64bit code is faster, because the x86_64 mode has more registers than the traditional i386. On the first gen Intel x86_64 CPUs, that would be P4's that had 64bit added to them, I'd probably stick with 32bit, but on any AMD or Intel Core CPU, I'd probably use x86_64 by default.
Scot P. Floess wrote:> I have a really silly question... but just want to ask... > > I have one box on my home network that is x86_64 capable... My other > boxes are all i386. As this x86_64 machine can, at most, house 4 GB of > RAM (currently only has 1 GB) - is there any advantage to my running > x86_64 on that machine instead of i386... Long story as to why I am > asking - but before I go off and moveit down to i386 - just wanted some > opinions :)Really depends on what you are going to use it for, my own home system is 3GB and runs i386 mainly for software compatibility reasons, my co-located server runs i386 with 6GB ram mainly because VMware doesn't support 64-bit mode on the older Xeons I have, so not a big point for me to go 64-bit(and memory usage is quite low anyways). Myself I make it a point when dealing with VMs at least to make them 32-bit unless they need a lot of memory, then I make them 64-bit. On any modern host I have they are all 64-bit, and typically have a minimum of 16-32GB of ram, so one would have to go to the nuthouse to run 32-bit on 16+GB of ram these days..my own cut off point, line in the sand for 32-64bit is 8GB. But certainly there are cases that you want 64-bit for even a system running 3GB(such as running a DB or VM process that uses a lot of memory). I would say stick to whatever your using now if it works, if the rest of your network is i386 and that one box is i386, and you could move it to x86_64, I would leave it at i386 myself. nate
John Thomas
2009-Dec-16 20:04 UTC
[CentOS] Desktop/Server 32/64 (was Re: Silly question x64 vs i386)
> I have one box on my home network that is x86_64 capable... My other > boxes are all i386. As this x86_64 machine can, at most, house 4 GB of > RAM (currently only has 1 GB) - is there any advantage to my running > x86_64 on that machine instead of i386... Long story as to why I am > asking - but before I go off and moveit down to i386 - just wanted some > opinions :)If I may hijack, what about desktop machines? Would your 32/64 choice be the same if it were primarily a desktop machine vs. primarily a server? I recall a year or so ago the answer was 32 bit for desktops, but perhaps that has changed. -- Sincerely, John Thomas
Scot P. Floess
2009-Dec-16 20:13 UTC
[CentOS] Desktop/Server 32/64 (was Re: Silly question x64 vs i386)
All my machines - including my desktop - are 32 bit. This lone x86_64 machine is a headless server (well I plug in a monitor from time to time) - but usually its headless (as are all my machines but my desktop)... On Wed, 16 Dec 2009, John Thomas wrote:>> I have one box on my home network that is x86_64 capable... My other >> boxes are all i386. As this x86_64 machine can, at most, house 4 GB of >> RAM (currently only has 1 GB) - is there any advantage to my running >> x86_64 on that machine instead of i386... Long story as to why I am >> asking - but before I go off and moveit down to i386 - just wanted some >> opinions :) > > If I may hijack, what about desktop machines? Would your 32/64 choice > be the same if it were primarily a desktop machine vs. primarily a > server? I recall a year or so ago the answer was 32 bit for desktops, > but perhaps that has changed. > > -- > Sincerely, > John Thomas > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos >Scot P. Floess 27 Lake Royale Louisburg, NC 27549 252-478-8087 (Home) 919-890-8117 (Work) Chief Architect JPlate http://sourceforge.net/projects/jplate Chief Architect JavaPIM http://sourceforge.net/projects/javapim Architect Keros http://sourceforge.net/projects/keros
> I have a really silly question... but just want to ask... > > I have one box on my home network that is x86_64 capable... My other > boxes are all i386. As this x86_64 machine can, at most, house 4 GB of > RAM (currently only has 1 GB) - is there any advantage to my running > x86_64 on that machine instead of i386... Long story as to why I am > asking - but before I go off and moveit down to i386 - just wanted some > opinions :)Short answer: yes. Longer answer: every single move, down at the machine/assembly level, can move twice as many bits as on a 32-bit system. That will show up as a very serious speed increase in your software. mark "why you should *always* have an assembler course"
At Wed, 16 Dec 2009 14:53:01 -0500 (EST) CentOS mailing list <centos at centos.org> wrote:> > I have a really silly question... but just want to ask... > > I have one box on my home network that is x86_64 capable... My other > boxes are all i386. As this x86_64 machine can, at most, house 4 GB of > RAM (currently only has 1 GB) - is there any advantage to my running > x86_64 on that machine instead of i386... Long story as to why I am > asking - but before I go off and moveit down to i386 - just wanted some > opinions :)With only 1gig of RAM there is little reason for 64-bit addressing -- 1 gig is well within the range of 32-bit addressing (yes, you could set up a large swap partition and have lots of virtual addressing, but swapping like 8 gig of VM in and out of 1 gig of physical RAM would be painful). Also, 64-bit apps tend to be a little larger then their 32-bit versions (fatter pointers, integers, etc.). With 1 gig memory will be a wee bit tighter (modern 64-bit machines would normally have lots more RAM...). With what is obvious and 'older' 64-bit system, being limited to 4gig of RAM (which is still just within 32-bit address space), going 64-bit with this system would not buy you much. If you want a consistent operating environment, especially if you don't want to maintain two separate sets of updates, keeping all of your boxes at 32-bit for the time being probably makes sense. If and when you upgrade things, going 64-bit might make sense.> > Scot P. Floess > 27 Lake Royale > Louisburg, NC 27549 > > 252-478-8087 (Home) > 919-890-8117 (Work) > > Chief Architect JPlate http://sourceforge.net/projects/jplate > Chief Architect JavaPIM http://sourceforge.net/projects/javapim > > Architect Keros http://sourceforge.net/projects/keros > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > >-- Robert Heller -- 978-544-6933 Deepwoods Software -- Download the Model Railroad System http://www.deepsoft.com/ -- Binaries for Linux and MS-Windows heller at deepsoft.com -- http://www.deepsoft.com/ModelRailroadSystem/
On Wed, 2009-12-16 at 14:53 -0500, Scot P. Floess wrote:> is there any advantage to my running > x86_64 on that machine instead of i386...A better question might be, do you have any particular reason not to run x86_64 on that machine? All of my machines and the machines that I look after are now running Centos x86_64, with the exception of one LTSP server and my Acer Aspire One laptop. The Acer netbook can't, of course, and the LTSP server runs dosemu which is much slower on x86_64. I just set up a new telephone answering system the other day and now it's x86_64 too. Not for any particular reason, but why not? The hardware can handle it and I see no reason not to. -- MELVILLE THEATRE ~ Melville Sask ~ http://www.melvilletheatre.com
On Wed, Dec 16, 2009 at 11:53 AM, Scot P. Floess <sfloess at nc.rr.com> wrote:> I have a really silly question... but just want to ask... > > I have one box on my home network that is x86_64 capable... ?My other > boxes are all i386. ?As this x86_64 machine can, at most, house 4 GB of > RAM (currently only has 1 GB) - is there any advantage to my running > x86_64 on that machine instead of i386... ?Long story as to why I am > asking - but before I go off and moveit down to i386 - just wanted some > opinions :) >The number of bits of the OS is insignificant when considering disk IO. I'd use the best disk controller (where best is determined by measurement) and slap into the machine with the most CPU's and make sure it has sufficient memory. In the end, if your disks suck, so will your IO regardless of what you do. -- Enjoy global warming while it lasts.
m.roth at 5-cent.us wrote:> Longer answer: every single move, down at the machine/assembly level, can > move twice as many bits as on a 32-bit system. That will show up as a very > serious speed increase in your software. >actually, the pentiums have had a 64bit physical memory bus since the first 60Mhz version, and all L1/L2 cache <=> physical memory operations are 64bits. the CPUs have all optimized things like REP MOVSB to move by 64bit chunks whenever possible. The main performance advantage of x86_64 vs i686 is in the additional general purpose registers, this allows the compiler (or assembler programmer) to minimize the number of load/store instructions to implement a given sequence of operations.
On 16/12/09 19:53, Scot P. Floess wrote:> I have a really silly question... but just want to ask... > > I have one box on my home network that is x86_64 capable... My other > boxes are all i386. As this x86_64 machine can, at most, house 4 GB of > RAM (currently only has 1 GB) - is there any advantage to my running > x86_64 on that machine instead of i386... Long story as to why I am > asking - but before I go off and moveit down to i386 - just wanted some > opinions :) > > Scot P. Floess > 27 Lake Royale > Louisburg, NC 27549 > > 252-478-8087 (Home) > 919-890-8117 (Work) > > Chief Architect JPlate http://sourceforge.net/projects/jplate > Chief Architect JavaPIM http://sourceforge.net/projects/javapim > > Architect Keros http://sourceforge.net/projects/keros > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > > >Personally, if you had asked this 3 years ago, I'd have said "Go i686" due to compatibility. But now-a-days with up-to-date distributions there isn't many packages that aren't for x86_64. Heck even flash finally got a x86_64 Linux version now :-D (Took them long enough though!) Any machine I have that can run in x86_64, I normally install a x86_64 OS, and recently, I haven't found anything I need that is only i686. And usually, when you *do* need a i686 package it's usually possible to install the i686 versions of the packages (depending on the repo of course) where a command such as: yum install httpd.i686 (or .i386 again depending on repo) would come in handy :-) and then you have the i686 version, though there not always stable like that :-| x86_64 has matured over the years and it's done it well :-) But then, personally, I'd say, keep the current OS, unless there is actually something that makes you actually need x86_64. As they say "If it ain't broke, Don't fix it". Though if you build/acquire a new x86_64 box, throw a x86_64 OS on it :-) But still, check make sure they are x86_64 binarys available. or sources that will compile on x86_64. In most cases, it will. Oh, and there's no such thing as a silly question ;-) -- Jake