Help: 64 bit Cacoa. What is means for user joe?

hkbaqhkbaq
Posted:
in macOS edited January 2014
Hi



i am wondering what it means that leopard is completely 64 bit. Say i am running the same NetNewsWire or Safari....would it instaneously run faster? or would the developer have to ship it 64bit ready. And if they do, does it mean it will be faster? how noticible is it to the plain eye.



How is this different from the 64 bit tiger?



thanks you guys

Comments

  • Reply 1 of 16
    sziwansziwan Posts: 25member
    64-bit is not necessarily faster. For most apps, the performance will be the same or even slightly lower (due to the larger code footprint). Currently, 64-bit is all about the memory. With 32 bits, an application can only allocate 4 GB (effectively 2.5-3 GB), with 64 your address space suddenly becomes much larger.



    And yes, the apps have to be recompiled to reap the benefits of a 64-bit CPU and operating system.
  • Reply 2 of 16
    davegeedavegee Posts: 2,765member
    I thought this was all but hashed out when the G5 reared it's head a few years ago...



    64bit support (primarily) does two major things.



    1 - Allow programs to utilize more than 4GB of ram

    2 - Allow programs to process 64 bit instructions



    Many of the Applications we use commonly today really wont benefit from either feature. Safari, Word, iTunes and the like will (for the most part) act/feel the same as a '32 bit app' or a '64 bit app' - same goes for much of the OS too.



    Applications that will benefit include:



    Photoshop and other memory hungry apps - if you feel you are pushing the app to the current memory limits 4GB (i think) then yes having more memory will help to a point and I suppose a FEW filter effects MAY be able to utilize 64 bit instructions to speed things up but with all things being equal, I don't see you magically getting a 2X speed boost just by running a 64 bit ready version of Photoshop on a 64 bit CPU over a comparable 32 bit setup.



    Database and other server type apps where access to GOBS and GOBS of memory will be a huge benefit but I don't think any of those applications will see a 2X speed boost.



    Scientific applications where being able to process a single 64 bit instruction (instead of having to split it up into 2 32 bit ones) - here we are really talking about an app that could magically run twice (almost) as fast as before (once that is when the app is properly written/rewritten to take advantage of a 64 bit CPU) -



    Crypto apps would also benefit since they too tend to deal with 64 bit ints.



    The fact is most of the apps we use on a daily basis just don't NEED the precision of 64 bit processing.



    ARS has a great (even if it's a few years old now) article on 64 bit computing - it explains this stuff and a lot more in much greater detail (and still fairly easy to comprehend).



    Link: http://arstechnica.com/cpu/03q1/x86-64/x86-64-1.html



    Dave
  • Reply 3 of 16
    chuckerchucker Posts: 5,089member
    64-bit means a wholly different thing on EM64T (aka x86-64/AMD64/x64). It's not just about the addressing. More registers become available, meaning apps can overall get faster — sometimes even 30%. All it takes is a recompile.
  • Reply 4 of 16
    davegeedavegee Posts: 2,765member
    ...



    removed since I was quoting information based on older (1st gen?) 64 bit CPUs



    ..
  • Reply 5 of 16
    chuckerchucker Posts: 5,089member
    That's misleading. It is correct that there is no inherent performance boost in 64-bitness; in fact, there can be a slight penalty.



    However, x86-64 provides for many more registers, and that can yield a big boost.
  • Reply 6 of 16
    davegeedavegee Posts: 2,765member
    Quote:
    Originally Posted by Chucker


    64-bit means a wholly different thing on EM64T (aka x86-64/AMD64/x64). It's not just about the addressing. More registers become available, meaning apps can overall get faster ? sometimes even 30%. All it takes is a recompile.





    Hmmmm well just when I thought I had a fair grasp on things the world has once again made a turn while I kept going straight... Okay - well what I quoted above was TRUE (at one time anyway).



    I guess it's time for me to find a new 64-bit CPU for dummies article that I can breeze thru. Anyone got any links?



    Dave
  • Reply 7 of 16
    chuckerchucker Posts: 5,089member
    What you said is completely true for architectures that were designed to allow for 64-bitness right from the start, such as PowerPC. PowerPC was, all the way back in 1991, capable of 32-bit and 64-bit.



    In the case of x86, however, 64-bit support is an add-on, and thus comes with heavy notifications, which as a neat side effect allow for more registers (of which PowerPC, in turn, has more to begin with). Hence the change.
  • Reply 8 of 16
    almightymacalmightymac Posts: 8member
    I'm not very well versed in the whole 32/64 bit thing. What does all this mean for someone who has an intel iMac? It's 32-bit right?
  • Reply 9 of 16
    wjmoorewjmoore Posts: 210member
    Quote:
    Originally Posted by AlmightyMac


    I'm not very well versed in the whole 32/64 bit thing. What does all this mean for someone who has an intel iMac? It's 32-bit right?



    AlmightyMac: You can happily ignore it. You Mac along with all the other non-Xeon ones are 32-bit and will continue to function as they do now.
  • Reply 10 of 16
    hkbaqhkbaq Posts: 58member
    so i guess well have to wait for those 64 bit MB P to stay on top of things....

    hope that photoshop comes out with 64 bit since they are already taking that long to release it....
  • Reply 11 of 16
    amoryaamorya Posts: 1,103member
    To the user, it means nothing. That's why it was announced at a developer conference.



    It may allow people to code certain, very specific, apps that run faster. But I wouldn't worry about that yourself (unless you do coding) -- if a developer codes a faster app, they'll market it as faster, not as "the new 64 bit hotness".



    It's a developer feature through and through.





    Amorya
  • Reply 12 of 16
    wmfwmf Posts: 1,164member
    Don't expect 64-bit apps to be 30% faster; according to the latest benchmarks, some apps are way faster but most are roughly the same performance or slower in 64-bit mode:



    http://www.xbitlabs.com/articles/cpu...duo-64bit.html



    (The Core 2 Extreme tested in the article is virtually the same as Apple's 3GHz Xeon.)
  • Reply 13 of 16
    theapplegeniustheapplegenius Posts: 584member
    What sucks about 64bit is the fact that you can really only use 25 percent of the processor. In most instances, 64bit is slower on Intel. EM64T would be better suited on K8 as it's more powerful then AMD64, but Core 2 only has 1 complex process thing. I'll hit up google and dig up some more, this is a terrible translation.
  • Reply 14 of 16
    chuckerchucker Posts: 5,089member
    Quote:
    Originally Posted by theapplegenius


    What sucks about 64bit is the fact that you can really only use 25 percent of the processor. In most instances, 64bit is slower on Intel. EM64T would be better suited on K8 as it's more powerful then AMD64, but Core 2 only has 1 complex process thing. I'll hit up google and dig up some more, this is a terrible translation.



    Huh? EM64T and AMD64 are the same.
  • Reply 15 of 16
    theapplegeniustheapplegenius Posts: 584member
    No they're not. EM64T has more instructions, AMD64 is more efficent.
  • Reply 16 of 16
    chuckerchucker Posts: 5,089member
    There are differences, but I still don't get your "better suited on K8" bit.
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