64-bit Linux?

[raid517]

Split from Ubuntu CD discussion here:

https://www.neowin.net/forum/index.php?showtopic=249963

Yes well it is a good idea, providing that is your genuine intention and you really do know that many people who want to use Linux. Personally most of the people I know have never heard of it.

But anyhoo, moving on... I noticed that they are offering Athlon 64bit enabled ISOs. It might seem like a stupid question but are these genuinely 64Bit compiled debian distros? Because 64Bit debian as far as I knew up until now was something of a rareity.

If it is I will certainly be ordering a copy for my laptop.

GJ

Edited November 29, 2004 by markjensen

[Lokheed]

Yes well it is a good idea, providing that is your genuine intention and you really do know that many people who want to use Linux. Personally most of the people I know have never heard of it.

But anyhoo, moving on... I noticed that they are offering Athlon 64bit enabled ISOs. It might seem like a stupid question but are these genuinely 64Bit compiled debian distros? Because 64Bit debian as far as I knew up until now was something of a rareity.

If it is I will certainly be ordering a copy for my laptop.

GJ

585005320[/snapback]

I doubt it. 64bit programs or OS' arent likely to be truely optimized for these new processors. They may run on 64bit archs but that doesnt mean they are specifically developed for them...

The whole 64bit hype is just that. Its going to take years before they are going to be utilized to their potential.

[raid517]

I doubt it. 64bit programs or OS' arent likely to be truely optimized for these new processors. They may run on 64bit archs but that doesnt mean they are specifically developed for them...

The whole 64bit hype is just that. Its going to take years before they are going to be utilized to their potential.

585005711[/snapback]

It isn't that odd... there are 64Bit folly compiled/enabled linux distros avaiable now. I mean I had hoped that someone would compile Debian soon - but this seemed to be the first solid news I've heard of it.

It is perfectly possible to compile Debian for 64Bit (the whole kaboodle - apps and everything) but I got the impression that the maintainers were waiting for individual distributers to take up the task - which is why I wonderd if this is what these guys have done?

GJ

[Lokheed]

Its perfectly possible to compile anything on a 64bit arch in Linux. Doesnt mean the software is optimized for it or takes advantage of anything 64bit offers above 32bit...

Just because something runs on 64bit, doesnt mean anything unless the program was written to take advantage of the architecture. Linux will be the first though, they always are. IPv6 if it launched tomorrow, would be fully supported in Linux...for example.

[raid517]

Well I currently have Gentoo installed on my laptop - and that is fully compiled for 64Bit. I should know, I set the compiler flags for all my applications and built the kernel myself. I would be very suprised if suddenly you were telling me that it isn't fully 64Bit enabled...

I know SuSe have a version that is fully 64Bit compiled - as do Mandrake, to name but a few. So it isn't all quite pie in the sky. 64Bit computing is already here - even if MS does seem to be taking an age to catch up.

GJ

[Lokheed]

Well I currently have Gentoo installed on my laptop - and that is fully compiled for 64Bit. I should know, I set the compiler flags for all my applications and built the kernel myself. I would be very suprised if suddenly you were telling me that it isn't fully 64Bit enabled...

I know SuSe have a version that is fully 64Bit compiled - as do Mandrake, to name but a few. So it isn't all quite pie in the sky. 64Bit computing is already here - even if MS does seem to be taking an age to catch up.

GJ

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You are listening but you arent hearing me.

Just because it works on 64bit, just because it compiles on 64bit, just because you have it running on 64bit, DOES NOT MAKE IT A TRUE 64BIT PROGRAM. This means that it is NOT going to offer you anything that the shlubb down the street running 32bit doesnt have. To write a TRUE 64bit code is VERY different then writing 32bit code and SUPPORTING 64bit.

Thats all you have right now...SUPPORT for 64bit. You dont have any improvments or advances on the 32bit software at all...it just runs on your 64bit arch...is that a little clearer?

Thats why 64bit is just a gimmick right now. Nothing is being wirtten for the arch yet and its going to be years before things move to it. Its only being supported and thats NOT the samething. You think Gentoo rewrote the Linux code, the kernel and their operating system in 64bit???

[n3wt]

You think Gentoo rewrote the Linux code, the kernel and their operating system in 64bit???

No, but they could have taken the same code, run it through a compiler on a 64 bit machine, thus creating 64 bit assembly.

I may be missing what you are trying to say, but entire programming languages, or programming paradigms do not change when you change the size of the registers on the chip. :/

[LaNcom]

I think what Lokheed means is that the applications are not written in a way that they would actually show any performance improvements when compiled for AMD64. While this is, in part, still true, a lot has changed recently. If an application is not ASM-optimized for 32bit x86, then it would benefit from the architectural improvements of AMD64 anyway (twice the registers, for example). But if an application uses 32bit ASM code, like xvid or MPlayer, they would perform worse in 64bit mode because the optimizations would not be available. Luckily, as the percentage of AMD64 systems increases, more and more apps are indeed optimized to take advantage. The current MPlayer CVS contains 64bit ASM code and is faster than the 32bit counterpart, same goes for Avidemux, ffmpeg, and xvid.

But that's mostly a problem with assembly optimizations, as, for C/ C++ code, there's a hardly anything you can do to take advantage of the 64bit. It's up to the compiler to do this, and GCC 3.4 was a huge improvement, with GCC 4.0 around the corner. You could, of course, write applications that use higher precision, but if 32bit precision is sufficient, going 64bit would not increase the speed and would also waste a lot of RAM - it might be possible that we'll see more applications using higher precision in the future (if developers find a need), as x86 was about the last 32bit one of the Linux supported archs, and it's finally dying...

Oh, and Lockheed: The Linux kernel is indeed written for AMD64 and benefits from the 64bits, as it supports 64bit archs for years now, anyway (like IA64, Sparc64, MIPS, Alpha, PPC64)...

[raid517]

You are listening but you arent hearing me.

Just because it works on 64bit, just because it compiles on 64bit, just because you have it running on 64bit, DOES NOT MAKE IT A TRUE 64BIT PROGRAM. This means that it is NOT going to offer you anything that the shlubb down the street running 32bit doesnt have. To write a TRUE 64bit code is VERY different then writing 32bit code and SUPPORTING 64bit.

Thats all you have right now...SUPPORT for 64bit. You dont have any improvments or advances on the 32bit software at all...it just runs on your 64bit arch...is that a little clearer?

Thats why 64bit is just a gimmick right now. Nothing is being wirtten for the arch yet and its going to be years before things move to it. Its only being supported and thats NOT the samething. You think Gentoo rewrote the Linux code, the kernel and their operating system in 64bit???

585009853[/snapback]

I don't quite get what you are saying - but then I'm not as technically 'up there with it all' as perhaps you are. Perhaps you would like to explain technically - for a non technical reader - exactly what you mean?

But I did pretty much as n3wt said and took the gentoo code base and built it on a 64 bit enabled compiler on a 64Bit machine, with a 64Bit enabled kernel (which I also compiled) and I set compiler flags to compile the whole thing from scratch (stage one) with 64Bit flags set in my compiler - so where exactly did I go wrong?

Indeed Gentoo is all about compiling everything from source from the first byte of code until the last - and my understanding is that they did indeed create a code base from sctach on x86/64 bit enabled hardware. So not only did they compile their entire code base on 64Bit arch - I then took that code and compiled it again - this time with compiler flags set to tailor it to my specific hardware.

Now if you are opening up this old debate about running 32Bit software with 64Bit extensions on a machine that also employs 64Bit extensions - then fair enough. But to be honest I'm not really that interested. So long as the OS I have is fully enabled and *capable*[/b} of utilising the specific archetecture I own, then I'm happy.

Perhaps for the purists here my question should have been does Ubuntu supply a Linux distro compiled to match my specific arch?

I would rather not have had to labour the point, but there you are.

GJ

[Lokheed]

Read LaNcom's post. He appearently says what I could not. Either way I am not interested in writing a ten page thread about archs, google it and read up on the entire 64bit "revolution" and look into your compiler. This entire discussion has way more depth then I have patience for. Debated with to many people about it...already giving me a headache as if you didnt follow my previous posts, then I am just going to be wasting my time anyway, sorry.

LaNcom: I have only recently got into Linux and am surprised they rewrote the kernel for the 64bit archs--actually not that surpised as Linux is always been the one to revolutionize software, 3rd party then just "steals" it and calls it their own. I am quite impressed. Something I am definetely going to have to look into. Thanks for the info.

[LaNcom]

Lockheed,

just check /usr/src/linux/arch and /usr/src/linux/include/asm*, there's the arch specific code for the Linux kernel. Most other parts of the kernel, like drivers and such, are written from the ground up to work on 64bit systems, and take an advantage where possible. Some parts are not, the ISA system is, AFAIK, 32bit only - but since there is no 64bit system using ISA, that's obvious...

[shihchiun]

What he's saying is this:

Sure, it runs on 64-bit processors, but it's got no performance gains over the regular 32-bit version. It's not optimized or anything, it just runs on the platform.

[raid517]

I think I disagree still somewhat. As has been pointed out there have been trully 64Bit enabled Linux distros avaiable for years now. AMD is something of a new kid on the block - and really it is only Intel and MS who are lagging behind. There are a whole bunch of 64Bit distros out there, for Solaris, For Mac, IA64 - and now for x86/64 - and for a whole load of other weird and wonderfull architectures - with companies such as Gentoo, SuSe Red Hat, Connectiva, Sun and Apple and several others having been in the game for quite a while. I am not sure it is entirely accurate to say they have no right to claim that there is any 64 bit functionality/optomisations built into what they commonly refer to as their 64 Bit code. Why then do they bother to make these claims?

I however do understand a little more than you think. I understand that not all of the packages I run are compiled fully for 64Bit functionality. (hence the x86/64Bit dual nature of the arch - which is intended to facilitate a transitional period - and which incidentally is also why I chose it). I understand that due to the way some of these applications are written there may indeed be a performance hit instead of a gain when running on a 64 bit platform, I understand also that developers need to develop specifically for 64Bit systems in order to utilise the full advantages that this new architecture offers. However as has also been pointed out, all of this is changing rapidly and there are indeed a great many packages that now are avialable and which are fully optomised for 64 Bit platforms.

This is only likely to continue to be the trend for much of the forseeable future - and given the often fantastic rate of development in Linux it may not be too far into the future before we really do have a fully functioning 64Bit desktop Linux system with all of the applications compiled and running in true 64Bit mode.

My own question was simply about Debian and Ubuntu - and that was if Ubuntu really was the first in the Debian world (although not the first in the Linux world) to instroduce a 64Bit 'aware' system?

Debian has always been seen as being traditionally more cautious than others about jumping on the bandwaggon when new things come out - but then even AMD's x86/64 Bit line isn't so new any more - so perhaps it would be around about this time that Debian developers would start to look at it more closely?

I am interested because despite having a nicely optomised Gentoo install on my laptop, Debian for it's ease of use is still my favorite distro.

It would be cool if Ubuntu were indeed to be the first company to deliver this.

GJ