AMD FX 2.2 gig 64 bit

Discussion in 'Computer Information' started by David Wells, Oct 19, 2003.

  1. David Wells

    DeMoN LaG Guest

    The point that I'm making is that you can take a 64-bit OS like Linux or
    Windows XP 64-bit, install a 64-bit database program on it and, without
    rebooting, disabling all things running that are 64-bits, flipping some
    switch or something, and simply double click the shortcut for calc.exe
    and run a 32 bit program at the same time. You are making it sound as
    though one still has to choose between /everything/ being recompiled and
    made 64-bits or not having any 64-bit support. AMD's own papers make
    this obvious that that is not the case, as 64-bit Compatibility Mode
    allows existing programs to run without being recompiled, yet still
    supports 64-bit programs. I imagine it would perform better in pure 64-
    bit mode or pure 32 bit mode due to less overhead, but I contend that
    AMD's papers say exactly what I just said. You can take a 64-bit OS, run
    a 64-bit application and a 32-bit application at the same time.

    This is a 6 page article on Windows XP 64-bit:
    http://www.gamepc.com/labs/view_content.asp?id=amd64xp&page=1

    The only part you are correct on is that Windows XP 64-bit does not allow
    32-bit drivers. One should note that this is entirely an OS limitation,
    and not a limitation of the CPU. Also note on page 4 this paragraph:

    Here's the beauty of the AMD64 architecture. Everything just works. No
    fuss, no hassle, no nothing. Just as the Opteron/Athlon 64 architecture
    can execute 32-bit and 64-bit code side by side, so can Windows XP 64-bit
    Edition for AMD64. You can be running a 32-bit applications right
    alongside a new 64-bit application, both running at full speed with no
    slowdowns. Everything, such as games, graphics applications, programming
    utilities, will run as seamlessly in XP 64-bit edition as they do in
    today's 32-bit editions of XP.


    I'm not sure how this argument has come about at this point. You claim
    the AMD64 architecture can not run 32-bit and 64-bit code at the same
    time. I've pointed to AMD documents that say it can, independant
    websites, and even a graph AMD made that shows it has two 64-bit modes,
    one where it supports 32 bit code and one where it is pure 64bit
    processing. You have shown no evidence at all and mince words and hack
    around the bush. 64-bit linux has been available for quite some time.
    The kernel is 64-bit. Most applications are getting to be compiled for
    64-bit. Some are not. They still run under 64-bit linux. Windows XP
    64bit is shown in that article as having a 64-bit and 32-bit executable
    installed by default.

    Unless you go and find some evidence that you are right, I'm going to
    just assume you are completely misinformed and rather than going "Hmm,
    these documents suggest contrary to what I said orginally, I suppose I
    was mistaken", you continue to argue without providing any evidence for
    your side of the argument.

    --
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    DeMoN LaG, Oct 21, 2003
    #21
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  2. David Wells

    derek / nul Guest

    That's easy, there is a bit in the status register for 64 bit.
    There is a separate machine status for each task, therefore each task can be 32
    or 64 bit. This is decided at task load time.
    to quote AMD

    With AMD64 technology, the AMD Athlon 64 processor is fully compatible with
    existing software, while enabling a seamless transition to upcoming 64-bit
    applications. Both 32- and 64-bit applications can run simultaneously and
    transparently on the same platform.

    NOTHING about running 32 bit code in 64 bit mode.
    Please find the quote, I have found several that say the opposite.
    Ok lets talk about that case with a single processor.

    Number one, 2 applications do NOT run at the same time, it is a multitasking
    environment.

    therefore 64 bit program runs when the machine state is loaded for that task,
    this included the 64 bit flag in that status register.

    Next a 32 bit program is run, its status register has the 32 bit flag set.

    So it can appear that 32 and 64 bit programs are running at the same time.
    Only some sales talk there
    You have misquoted me there.

    I said the processor cannot run 32 code in 64 bit mode.
    We will see if you can answer my stuff presented here.
     
    derek / nul, Oct 21, 2003
    #22
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  3. David Wells

    DeMoN LaG Guest

    Apparently we've had a misunderstanding. What I am saying is:
    You can run a 32 bit program at the same time as a 64 bit program. As in,
    I can open a 64 bit CAD program while using a 32 bit instant messaging
    program without having to reboot or close all 64 bit programs.
    What I think you are saying:
    The 32 bit code is still run as 32 bit code and doesn't gain any 64 bit
    benefits.

    If this is basically what we are saying, I agree entirely. My point is
    (and has been) that you can use one 64 bit OS and run both 64 and 32 bit
    programs inside that OS together without any problems, or crappy emulation
    that slows things down. You are (more or less) nitpicking that they are
    truly being run simulatenously and the 32 bit code is still executed as 32
    bit code. This is all true, but you say that 32 bit code isn't run in 64
    bit mode. It is. 64-bit "Compatibility mode". Whether the processor
    processes it as a 64 bit instruction or a 32 bit instruction isn't really
    relevant, as it is still in 64-bit mode.

    Do we agree that I can open and use both my 32 bit calculator and instant
    messaging software while browing the web in my 64-bit IE with my 64-bit CAD
    application processing stuff?

    --
    AIM: FrznFoodClerk (actually me)
    email: [email protected]_cast.net (_ = m)
    website: under construction
    Need a technician in the south Jersey area?
    email/IM for rates/services
     
    DeMoN LaG, Oct 21, 2003
    #23
  4. David Wells

    derek / nul Guest

    That's good.
    For all appearances, yes
    Only problem there is that the 64 bit OS is not running the 32 bit program
    directly, the AMD processor is.

    Get a 64 bit Intel processor with the same OS and see what you get.
    If you have a look at
    http://www.amd.com/us-en/Processors/ProductInformation/0,,30_118_9485_9488^9494,00.html
    It suggests that there are separate 32 and 64 bit instructions. If this is the
    case, then the 32 bit code CANNOT be run in 64 bit mode or compatibility mode.
    It is relevant to my argument.
    Absolutely
     
    derek / nul, Oct 22, 2003
    #24
  5. David Wells

    DeMoN LaG Guest

    I was implying that. The IA64 architecture does not support natively
    running x86 code, and implements it all through very slow emulation.

    I don't think that AMD link is what we are discussing. In 64-bit Long
    mode, no 32 bit code can be run. In 64-bit compatibility mode, 32 bit code
    can be run natively. I do not believe that it switches back to 32 bit mode
    during run time, as I imagine that would be very hard to design. Look at
    the graph I posted a link to previously, look at the address sizes and GPR
    sizes for 64-bit Compatibility mode. In long mode, both are 64 bits. In
    compat mode, both are 32 bits. I believe the processor implements compat
    mode by special casing 64-bit programs, and doing special stuff to run
    them, as opposed to doing something special to run a 32 bit program. I
    don't know how to explain what I'm saying really. I think I'm saying 64-
    bit compat mode is closer to 32 bit than to 64 bit.

    --
    AIM: FrznFoodClerk (actually me)
    email: [email protected]_cast.net (_ = m)
    website: under construction
    Need a technician in the south Jersey area?
    email/IM for rates/services
     
    DeMoN LaG, Oct 22, 2003
    #25
  6. David Wells

    derek / nul Guest

    The 32 bit instructions are all different from the 64 bit instructions.
    No need for switching modes.
     
    derek / nul, Oct 22, 2003
    #26
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