How 64-bit Are 64-bit distributions ?

devangdevang · #1 21st April 2007, 11:02 PM

I have been using 32-bit processors and 32-bit distributions. Of late, AMD x64 is the norm, I don't know if AMD even sells any 32-bit processors, at least in North America, any more. Even the Core2 from Intel is supposed to be x64-ish, although they have renamed their extension to call it their own invention.

Anyways, My question here is this.

How 64-bit are the 64-bit distributions ? When one downloads a "x86_64" distribution, does it mean it has maximum applications compiled for 64-bit ?

I know the kernels are compiled for 64-bit, but is it true for all the applications ? All the applications may not be able to successfully port to 64-bit, however, are the applications that can take advantage of 64-bit, such as multimedia, X-server, etc. compiled to 64-bit binary ?

In short, while the processor and motherboard hardware is mostly 64-bit, has the software caught up with it ? if so, how much ?

BNiels707 · #2 23rd April 2007, 03:44 AM

That isn't really a question that I feel can be answered to your satisfaction...but I'll try!

Fedora 6 x86_64 is pretty 64 bit. The majority of applications that can be easily compiled for 64 bit are. However, any program that can benefit from still maintaining its 32 bit legacy for compatibility or due to inability to compile for a 64 bit target is maintained. The biggest example of this would be Firefox which is still installed with both 32 and 64 bit compilations.

However, if you are focused on applications being compiled for a 64 bit target, you are missing the biggest point (at least from my standpoint as a developer) of a 64 bit platform, the availability to address significantly larger amounts of RAM. Granted, extensions and workarounds have been kludged into the 32 bit world to allow programs to utilize more than 3 gigs per process, however, the 64 bit instruction sets make the use of more RAM elegant and efficient. As a developer, I can now write an application that does some fairly heavy duty calculations and not worry about the fact the process is chewing away at 5 or 6 gigs of RAM (unless I want to use the workstation for something else...). Additionally, I can natively use longs instead of 32 bit integers.

I guess I've rambled a bit, and probably haven't answered your questions at all.

Anyway, I guess its 64-bit distributions are about 60% 64 bit...

devangdevang · #3 24th April 2007, 07:25 PM

Thank you BNiels. Now all I have to do is to go to the Sun web site to find out if they have a 64-bit compiled version of JRE.

JN4OldSchool · #4 24th April 2007, 07:33 PM

Interesting OP though and I still wonder a few things. I have been around Linux long enough now that I can pretty much fix anything I break. I am still using 32 bit. Am I really missing anything yet? 64 bit has been out a while now, are the apps now there, are they noticable quicker? I guess the FF problem hasnt been fixed, namely flash, but are there any other associeated problems with 64 bit these days? I havent seen a 32vs64 bit flamewar in some time, lets hash this out. Please, dont just troll though, give real reasons to support why I should move to 64 bit with F7 or that I should just continue on with 32 bit. I keep telling myself i will make that jump with every release but I always chicken out. The gain just doesnt seem worth the pain at this point. Not yet. Am I wrong? Are we there yet?

Seve · #5 24th April 2007, 07:54 PM

Quote:

Originally Posted by JN4OldSchool

The gain just doesnt seem worth the pain at this point. Not yet. Am I wrong? Are we there yet?

Hello JN4:
I believe you are on the right path.
I have run both from FC4 and although there has been great improvements over that time, the juice is still not worth the squeeze.
I think this is even more relevant, for new users - start with the 32bit.
Just my humble opinion and I am sure others will bring some different perspectives.

Seve

brunson · #6 24th April 2007, 11:02 PM

It's been argued on the Solaris 10 forums that running 64 bit versions of the OS and applications is actually slower slower because for every register operation you are moving twice as many bits. Especially in a context switch, which requires the OS to save all current registers to memory, then move the new applications context into register, 64 bit registers require twice as much data to move across the bus. My desktop system right here is currently performing ~3000 context switches per second.

If you don't need to access more than 4GB of memory and are not accessing files of >4TB, then running 64 bits could actually degrade your performance. All that being said, it's probably almost imperceptible to a casual user.

BNiels707 · #7 25th April 2007, 04:07 AM

I notice a performance improvement on some pretty high-test research based applications. I run a 64 bit OS whenever possible since its what I use when I work.

I find my 64 bit box to be every bit as snappy (if not moreso) then when I used to run 32 bit boxes.

That being said, I don't have any reason for people running 32 bit distros happily to make the switch.

Jman · #8 25th April 2007, 03:51 PM

It is entirely possible to make a Fedora x86_64 system all 64 bit by doing

Code:

yum remove '*.i386'

BNiels707 · #9 25th April 2007, 08:49 PM

Yes, you can do this, but then multilib will be completely worthless.

Not that multilib not working would be a huge crisis to most people, but proceed at your own risk.

jcliburn · #10 26th April 2007, 01:55 AM

The rule of thumb for Fedora multilib packages is found here: https://www.redhat.com/archives/fedo.../msg01203.html

I've done what Jman suggests with no ill effects, other than the loss of flash and java browser plugins. I also added "exclude=*.i?86" to my yum.conf file to keep the 32-bit stuff out. I do this only because I don't need the 32-bit packages, so it's a waste of bandwidth and disk space to install them on my system.

almackska · #11 29th April 2007, 05:11 AM

Is there a way tp upgrade my X86 system to X86_64 bit? I have an athlon 64 bit 3800+ and 4 gigs ram.

Seve · #12 29th April 2007, 05:17 AM

Hello:
I installed a 32 bit version, But how do i upgrade to X86_64 bit version?

Seve

joe.pelayo · #13 29th April 2007, 05:59 AM

Quote:

Originally Posted by JN4OldSchool

Interesting OP though and I still wonder a few things. I have been around Linux long enough now that I can pretty much fix anything I break. I am still using 32 bit. Am I really missing anything yet? 64 bit has been out a while now, are the apps now there, are they noticable quicker? I guess the FF problem hasnt been fixed, namely flash, but are there any other associeated problems with 64 bit these days? I havent seen a 32vs64 bit flamewar in some time, lets hash this out. Please, dont just troll though, give real reasons to support why I should move to 64 bit with F7 or that I should just continue on with 32 bit. I keep telling myself i will make that jump with every release but I always chicken out. The gain just doesnt seem worth the pain at this point. Not yet. Am I wrong? Are we there yet?

I had those same questions before. I got a 64 bits processor here in the laptop and wanted to know the 'difference' between 32 and 64 bits. I installed Mandriva 2007 64 bits and the only 'bonus' I had on it is that some applications crashed very often (the GIMP is the one I remember and can almost remember how to make it crash) I think due to a 'poor' 64 bits 'translation' because somewhere I used the same Mandriva but 32 bits and it worked 'fine'.

That's why I am now using 32 bits OS's only, until there comes the 'killer app' or a real need for 64 bits performance.

Thanks.
Joe.

keeler1 · #14 29th April 2007, 06:32 AM

Dont some x64 packages require their i386 counterparts to install. The nvidia drivers for example required me to download both the i386 and x86_64 parts in order to install it. So by removing all the i386 packages wouldnt I be removing my ability to use the nvidia drivers?

There have been other instances where the x86_64 packages installed the i386 as well. So removing all i386 would disallow the use of many packages. Correct?

BNiels707 · #15 30th April 2007, 06:58 PM

I am not positive about 64 bit packages being dependent on their 32 bit counterparts. I know some packages list the 32 bit counterpart as a dependency to ensure the proper functioning of multilib. I don't believe you would actually break any application by not installing both packages (but like I said, I am not positive).

I know that for video drivers it is recommended you install both sets of packages so that you get everything needed for both 32 bit and 64 bit apps to utilize 3D acceleration.