AMD64 version, is there really an advantage?

halma · n00b Joined: 04 Jul 2006 Posts: 3 Location: Earth

I have a 64-bit processor (AMD Athlon 64 3200+). Is there any distinct advantage to installing the AMD64 version of Gentoo, and compiling everything in 64-bit?

I'm thinking that perhaps it could even be slower, because pointers would be 8-bytes instead of 4, therefore in effect halving the CPU memory cache.

I have a new gentoo installation, I installed emacs off of the AMD64 package CD, and it's the slowest emacs I have ever seen; it takes about 5 seconds to load!

blubb

stringbean · n00b Joined: 17 Apr 2005 Posts: 9

halma - It all depends on what you do with your machine. Is your machine primarily for gaming, a server or what? 64 bit Gentoo has some performance gains over 32 bit but it all depends on what you are using the system for. There is no simple yes/no answer (dispite what blubb might say).

You say that you 'installed' off the AMD64 package CD and it ran extremely slowly. How on earth did you manage that if you are running 32 bit? You must have a 64 bit kernel to run 64 bit apps on!

gametime · n00b Joined: 12 Mar 2005 Posts: 24

It might just be me, but I've installed both 32-bit and 64-bit on my AMD64 machine and noticed quite a big difference in the time it took to compile things.

I also notice when i handle really large image sizes in gimp & inkscape that it handles that faster too. So far the only draw back to compiling everything 64-bit has been that I haven't gotten flash working in firefox but I don't really care about flash.

Jfr0 · n00b Joined: 19 Dec 2005 Posts: 72

Some programs are way faster on 64 bit. GMP is one example. Overall you probably wont notice too much of a change for regular use, but it does have some distinct advantages in some areas.

Janax · Apprentice Joined: 17 Aug 2004 Posts: 162 Location: Iowa

Just as a word of advice, you CAN get flash working by simply using '*-bin' packages. I basically use 'openoffice-bin' and 'mozilla-firefox-bin' all the time because I need to use flash (and MS Office capability) at work. Solves all my problems for me!
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luispa · Guru Joined: 17 Mar 2006 Posts: 359 Location: España

I'm really happy after I moved to 64. I've notice improvement (performance) when dealing with pictures, movies (mencoder), compilations and overall system.

luis

halma · n00b Joined: 04 Jul 2006 Posts: 3 Location: Earth

Thank you for your replies.

Bluekkis · n00b Joined: 09 Oct 2004 Posts: 33

jthompson · Posted: Thu Jul 06, 2006 6:44 pm Post subject:

Well I'm posting just to post I guess... waiting on a download.

I do know of one area that 64 bit will give you some benefit. Lets say you have a server that uses or NEEDS more than 4GB of RAM. Then it will definitely give you some performance gains.

There is also some technical articles on the Gentoo AMD64 FAQ. Just look for the question that you posed, "Will I see a difference?"

http://www.gentoo.org/doc/en/gentoo-amd64-faq.xml#perfup

Like most people say, its really all dependant on what you do and whether the software you use the most has been "optimized" to take advantage of the fancy smancy features in the hardware.

For some odd reason, hardware features always seems to be ahead of software development... but I digress.
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OddFox · Posted: Fri Jul 07, 2006 12:33 am Post subject:

If you do a lot of work with multimedia then you will see a speed increase. If you do a lot of gaming it's a mixed bag with the results usually ending up with a stalemate between 32-bit and 64-bit. If you have a server that sees lots of usage, you will probably get better performance in 64-bit. For your average desktop usage scenarios, web browsing and checking e-mail, you will not see a difference.

Quite frankly, there's not really any reason not to simply use a 64-bit environment if you have the hardware requirements and at least 1GB of RAM (Not that 64-bit OSes require that much, it's just a comfort level I myself have. 512MB would most likely be fine, but 1GB is dirt cheap these days and more often than not comes standard in prebuilt machines). Multimedia capabilities? You can have mplayer-bin and mplayer side-by-side until some video codecs finally get rewritten into 64-bit. Flash in your browser? Use Opera, it's free and only available in a 32-bit binary. 32-bit code does not incur any penalties being run in a 64-bit environment.

P.S. -- There's Firefox-bin and Mozilla-bin for the Gecko lovers out there. I find Opera to be more compatible, myself.
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SteveBallmersChair · Posted: Sun Aug 20, 2006 2:46 am Post subject:

I run the AMD64 version of Gentoo on my Athlon X2 box and it runs like greased lightning- until it is left running for about 3 weeks and the 2GB of RAM I have in the box gets filled up. Then performance goes down some as it occasionally has to swap to disk. I'd suggest 4GB of RAM on an AMD64 box that has to stay up for any length of time and gets used hard.
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andrewd18 · Posted: Sun Aug 20, 2006 3:33 am Post subject:

i92guboj · Posted: Sun Aug 20, 2006 4:08 am Post subject:

SteveBallmersChair · Posted: Sun Aug 20, 2006 4:12 am Post subject:

Nope, no Gecko here- I use Konqueror and the rest of the KDE gang. The memory usage seems to have stuck at ~150-200MB free as in not application memory and a few hundred MB of my 6GB striped-over-two-drives swap used.
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neuron · Advocate Joined: 28 May 2002 Posts: 2371

well, you have a memory leak, amd64 arch does not require anywhere near that much memory. (And also seing the memory increase over 3 weeks and not go back down.. defenatly a leak).

Headrush · Posted: Sun Aug 20, 2006 6:33 pm Post subject:

andrewd18 · Posted: Sun Aug 20, 2006 8:59 pm Post subject:

i92guboj · Posted: Sun Aug 20, 2006 9:21 pm Post subject:

SteveBallmersChair · Posted: Sun Aug 20, 2006 9:30 pm Post subject:

Headrush · Posted: Sun Aug 20, 2006 9:32 pm Post subject:

SteveBallmersChair · Posted: Sun Aug 20, 2006 9:41 pm Post subject:

i92guboj · Posted: Sun Aug 20, 2006 10:21 pm Post subject:

There is nothing wrong with that in a first view. Kio-slaves are multithreaded, so it is not strange that some similar procs are shown. Most of the memory is shared memory, so, dont worry about them.

If you just resetted I would leave top open laying somewhere and look from time to time to see if any programs increases the amount of memory it uses in an insane way over the time. Maybe is something that degradates with the time, in that case, since you just rebooted you will need to wait a bit and see what happens. Just do what you usually do with your box in the while. If there is a memory leak in some way, it will show itself over time.

SteveBallmersChair · Posted: Sun Aug 20, 2006 10:42 pm Post subject:

Thanks. I'll keep using the machine and in about another 2 weeks, let you know if it's still doing okay to diagnose where the RAM is going.
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Simius · Posted: Mon Aug 21, 2006 3:17 pm Post subject: Reclaiming lost memory

I think Linux reclaims all "lost" memory upon killing the leaky process. So if I'm not mistaken, all memory leaks are solved by an appropriate killall something -sigkill... No need to reboot.
Or is there?

BTW, I have just finished an amd_64 arch install with an Opteron 165 overclocked to HTT 250Mhz, and God help me it's FAST! So fregging, bloody FAST I could barely beleive it... I rebuilt stage1 and stage2 in less than 4 hours!
Don't know if it would be much slower with an x86 Linux, but... honestly, it can't be much faster than this.