64-bit still memory limited?

Discussion in 'Windows 64bit' started by =?Utf-8?B?TWFyaw==?=, Aug 15, 2007.

  1. I'm probably out of my league, but when did that ever stop someone from
    posting. (Yes, there is a question at the end of the post.)
    [Note: Also posted in General Discussion.]

    Computers have three main buses:
    Control Bus
    Data Bus
    Address Bus

    Control Bus is 16 bits wide and tells the address bus what method of
    communication is required (32-bit or 48-bit)for the device currently seeking
    to control the data bus.

    Data Bus is 64-bits wide, but typically cannot find anything to talk to
    wider than 32-bits other than the main processor which for most systems is
    also working in 32-bit mode.

    Address Bus is 48-bits wide and typically operates in one of two modes:
    32-bit or 48-bit. This method of operation depends on the Control Bus'
    instructions. 32-bit for peripheral devices. 48-bit for the main processor.
    In theory, 48-bit could access 2^48 addresses. (65,536 * 4GB) But, those
    darned peripheral chips force the control bus to limit the address bus to
    32-bit or 4GB.

    Peripheral devices (video card, sound card, modem, etc.) are hard coded to
    work in 32-bit. If your OS is 64-bit, then the drivers must be in 64-bit to
    ensure information sent to the peripheral device is formatted in a manner it
    can understand. Information from the device must be padded to 64-bit. And the
    control bus must be told it is still a 32-bit device. If the device is
    actually a 64-bit device (extremely rare) then the control bus is told it is
    a 64-bit device and lets the address bus do it's thing.

    But, 32-bit hardware changes how the address bus works. (Fixed with 64-bit
    drivers.) The upper 16 bits of the address bus become a means of identifying
    the device, mode of communication, etc. (essentially, paging mode for these
    devices to allow more than 4GB of memory to be addressed) and shift data
    transfer to a two iteration process (slowing things down.) Vendors understand
    this and design hardware to gain the speed of the processor by memory-mapping
    their hardware into RAM addresses so that the address bus does not shift to
    two step mode when sending or retrieving information to and from that device.
    This memory mapping reduces available RAM since the addresses cannot exist in
    duplicate.

    Based on this (probably flawed logic), it does not appear to me that
    converting to 64-bit Vista will improve my memory situation unless I actually
    install more than 4GB of memory to get above the peripheral devices memory
    mapping "window." Until then, the memory mapping of the peripheral devices
    still eats the RAM between 3GB and 4GB.

    Is this correct?
    Are 64-bit Vista users seeing 4 GB of RAM or the 3.2 GB "limit" with 4GB of
    RAM installed?
    =?Utf-8?B?TWFyaw==?=, Aug 15, 2007
    #1
    1. Advertising

  2. My Vista Ultimate, Business and Windows Server 2008 x64 systems are all seing
    my 4 GB RAM.
    It has been this way since day 1, two years ago.
    Intel chipsets (i955X and i975X), no memory remapping setting in BIOS.

    --
    Asus P5WDG2 WS Pro (i975X Express)
    Coreâ„¢ 2 Extreme X6800
    RAPTOR 2x150 GB RAID 0
    4GB DDR2 800MHz
    GeForce 8800GTX (163.11+165.01)
    Enermax 1000W 75A@+12V
    LAN 100/100
    XP x64 dualboot Vista x64


    "Mark" wrote:

    > I'm probably out of my league, but when did that ever stop someone from
    > posting. (Yes, there is a question at the end of the post.)
    > [Note: Also posted in General Discussion.]
    >
    > Computers have three main buses:
    > Control Bus
    > Data Bus
    > Address Bus
    >
    > Control Bus is 16 bits wide and tells the address bus what method of
    > communication is required (32-bit or 48-bit)for the device currently seeking
    > to control the data bus.
    >
    > Data Bus is 64-bits wide, but typically cannot find anything to talk to
    > wider than 32-bits other than the main processor which for most systems is
    > also working in 32-bit mode.
    >
    > Address Bus is 48-bits wide and typically operates in one of two modes:
    > 32-bit or 48-bit. This method of operation depends on the Control Bus'
    > instructions. 32-bit for peripheral devices. 48-bit for the main processor.
    > In theory, 48-bit could access 2^48 addresses. (65,536 * 4GB) But, those
    > darned peripheral chips force the control bus to limit the address bus to
    > 32-bit or 4GB.
    >
    > Peripheral devices (video card, sound card, modem, etc.) are hard coded to
    > work in 32-bit. If your OS is 64-bit, then the drivers must be in 64-bit to
    > ensure information sent to the peripheral device is formatted in a manner it
    > can understand. Information from the device must be padded to 64-bit. And the
    > control bus must be told it is still a 32-bit device. If the device is
    > actually a 64-bit device (extremely rare) then the control bus is told it is
    > a 64-bit device and lets the address bus do it's thing.
    >
    > But, 32-bit hardware changes how the address bus works. (Fixed with 64-bit
    > drivers.) The upper 16 bits of the address bus become a means of identifying
    > the device, mode of communication, etc. (essentially, paging mode for these
    > devices to allow more than 4GB of memory to be addressed) and shift data
    > transfer to a two iteration process (slowing things down.) Vendors understand
    > this and design hardware to gain the speed of the processor by memory-mapping
    > their hardware into RAM addresses so that the address bus does not shift to
    > two step mode when sending or retrieving information to and from that device.
    > This memory mapping reduces available RAM since the addresses cannot exist in
    > duplicate.
    >
    > Based on this (probably flawed logic), it does not appear to me that
    > converting to 64-bit Vista will improve my memory situation unless I actually
    > install more than 4GB of memory to get above the peripheral devices memory
    > mapping "window." Until then, the memory mapping of the peripheral devices
    > still eats the RAM between 3GB and 4GB.
    >
    > Is this correct?
    > Are 64-bit Vista users seeing 4 GB of RAM or the 3.2 GB "limit" with 4GB of
    > RAM installed?
    >
    =?Utf-8?B?TWFyYXRvbm1hbm5lbg==?=, Aug 15, 2007
    #2
    1. Advertising

  3. Thanks!
    I'm assuming the two years ago wasn't Vista... :)

    "Maratonmannen" wrote:

    > My Vista Ultimate, Business and Windows Server 2008 x64 systems are all seing
    > my 4 GB RAM.
    > It has been this way since day 1, two years ago.
    > Intel chipsets (i955X and i975X), no memory remapping setting in BIOS.
    >
    > --
    > Asus P5WDG2 WS Pro (i975X Express)
    > Coreâ„¢ 2 Extreme X6800
    > RAPTOR 2x150 GB RAID 0
    > 4GB DDR2 800MHz
    > GeForce 8800GTX (163.11+165.01)
    > Enermax 1000W 75A@+12V
    > LAN 100/100
    > XP x64 dualboot Vista x64
    >
    >
    > "Mark" wrote:
    >
    > > I'm probably out of my league, but when did that ever stop someone from
    > > posting. (Yes, there is a question at the end of the post.)
    > > [Note: Also posted in General Discussion.]
    > >
    > > Computers have three main buses:
    > > Control Bus
    > > Data Bus
    > > Address Bus
    > >
    > > Control Bus is 16 bits wide and tells the address bus what method of
    > > communication is required (32-bit or 48-bit)for the device currently seeking
    > > to control the data bus.
    > >
    > > Data Bus is 64-bits wide, but typically cannot find anything to talk to
    > > wider than 32-bits other than the main processor which for most systems is
    > > also working in 32-bit mode.
    > >
    > > Address Bus is 48-bits wide and typically operates in one of two modes:
    > > 32-bit or 48-bit. This method of operation depends on the Control Bus'
    > > instructions. 32-bit for peripheral devices. 48-bit for the main processor.
    > > In theory, 48-bit could access 2^48 addresses. (65,536 * 4GB) But, those
    > > darned peripheral chips force the control bus to limit the address bus to
    > > 32-bit or 4GB.
    > >
    > > Peripheral devices (video card, sound card, modem, etc.) are hard coded to
    > > work in 32-bit. If your OS is 64-bit, then the drivers must be in 64-bit to
    > > ensure information sent to the peripheral device is formatted in a manner it
    > > can understand. Information from the device must be padded to 64-bit. And the
    > > control bus must be told it is still a 32-bit device. If the device is
    > > actually a 64-bit device (extremely rare) then the control bus is told it is
    > > a 64-bit device and lets the address bus do it's thing.
    > >
    > > But, 32-bit hardware changes how the address bus works. (Fixed with 64-bit
    > > drivers.) The upper 16 bits of the address bus become a means of identifying
    > > the device, mode of communication, etc. (essentially, paging mode for these
    > > devices to allow more than 4GB of memory to be addressed) and shift data
    > > transfer to a two iteration process (slowing things down.) Vendors understand
    > > this and design hardware to gain the speed of the processor by memory-mapping
    > > their hardware into RAM addresses so that the address bus does not shift to
    > > two step mode when sending or retrieving information to and from that device.
    > > This memory mapping reduces available RAM since the addresses cannot exist in
    > > duplicate.
    > >
    > > Based on this (probably flawed logic), it does not appear to me that
    > > converting to 64-bit Vista will improve my memory situation unless I actually
    > > install more than 4GB of memory to get above the peripheral devices memory
    > > mapping "window." Until then, the memory mapping of the peripheral devices
    > > still eats the RAM between 3GB and 4GB.
    > >
    > > Is this correct?
    > > Are 64-bit Vista users seeing 4 GB of RAM or the 3.2 GB "limit" with 4GB of
    > > RAM installed?
    > >
    =?Utf-8?B?TWFyaw==?=, Aug 15, 2007
    #3
  4. It was Vista.
    I was a beta-tester from the beginning. And I always did run 64-bit, just to
    see my all 4. :)

    --
    Asus P5WDG2 WS Pro (i975X Express)
    Coreâ„¢ 2 Extreme X6800
    RAPTOR 2x150 GB RAID 0
    4GB DDR2 800MHz
    GeForce 8800GTX (162.18+165.01)
    Enermax 1000W 75A@+12V
    LAN 100/100
    XP x64 dualboot Vista x64


    "Mark" wrote:

    > Thanks!
    > I'm assuming the two years ago wasn't Vista... :)
    >
    > "Maratonmannen" wrote:
    >
    > > My Vista Ultimate, Business and Windows Server 2008 x64 systems are all seing
    > > my 4 GB RAM.
    > > It has been this way since day 1, two years ago.
    > > Intel chipsets (i955X and i975X), no memory remapping setting in BIOS.
    > >
    > > --
    > > Asus P5WDG2 WS Pro (i975X Express)
    > > Coreâ„¢ 2 Extreme X6800
    > > RAPTOR 2x150 GB RAID 0
    > > 4GB DDR2 800MHz
    > > GeForce 8800GTX (163.11+165.01)
    > > Enermax 1000W 75A@+12V
    > > LAN 100/100
    > > XP x64 dualboot Vista x64
    > >
    > >
    > > "Mark" wrote:
    > >
    > > > I'm probably out of my league, but when did that ever stop someone from
    > > > posting. (Yes, there is a question at the end of the post.)
    > > > [Note: Also posted in General Discussion.]
    > > >
    > > > Computers have three main buses:
    > > > Control Bus
    > > > Data Bus
    > > > Address Bus
    > > >
    > > > Control Bus is 16 bits wide and tells the address bus what method of
    > > > communication is required (32-bit or 48-bit)for the device currently seeking
    > > > to control the data bus.
    > > >
    > > > Data Bus is 64-bits wide, but typically cannot find anything to talk to
    > > > wider than 32-bits other than the main processor which for most systems is
    > > > also working in 32-bit mode.
    > > >
    > > > Address Bus is 48-bits wide and typically operates in one of two modes:
    > > > 32-bit or 48-bit. This method of operation depends on the Control Bus'
    > > > instructions. 32-bit for peripheral devices. 48-bit for the main processor.
    > > > In theory, 48-bit could access 2^48 addresses. (65,536 * 4GB) But, those
    > > > darned peripheral chips force the control bus to limit the address bus to
    > > > 32-bit or 4GB.
    > > >
    > > > Peripheral devices (video card, sound card, modem, etc.) are hard coded to
    > > > work in 32-bit. If your OS is 64-bit, then the drivers must be in 64-bit to
    > > > ensure information sent to the peripheral device is formatted in a manner it
    > > > can understand. Information from the device must be padded to 64-bit. And the
    > > > control bus must be told it is still a 32-bit device. If the device is
    > > > actually a 64-bit device (extremely rare) then the control bus is told it is
    > > > a 64-bit device and lets the address bus do it's thing.
    > > >
    > > > But, 32-bit hardware changes how the address bus works. (Fixed with 64-bit
    > > > drivers.) The upper 16 bits of the address bus become a means of identifying
    > > > the device, mode of communication, etc. (essentially, paging mode for these
    > > > devices to allow more than 4GB of memory to be addressed) and shift data
    > > > transfer to a two iteration process (slowing things down.) Vendors understand
    > > > this and design hardware to gain the speed of the processor by memory-mapping
    > > > their hardware into RAM addresses so that the address bus does not shift to
    > > > two step mode when sending or retrieving information to and from that device.
    > > > This memory mapping reduces available RAM since the addresses cannot exist in
    > > > duplicate.
    > > >
    > > > Based on this (probably flawed logic), it does not appear to me that
    > > > converting to 64-bit Vista will improve my memory situation unless I actually
    > > > install more than 4GB of memory to get above the peripheral devices memory
    > > > mapping "window." Until then, the memory mapping of the peripheral devices
    > > > still eats the RAM between 3GB and 4GB.
    > > >
    > > > Is this correct?
    > > > Are 64-bit Vista users seeing 4 GB of RAM or the 3.2 GB "limit" with 4GB of
    > > > RAM installed?
    > > >
    =?Utf-8?B?TWFyYXRvbm1hbm5lbg==?=, Aug 15, 2007
    #4
  5. =?Utf-8?B?TWFyaw==?=

    Guest

    On Aug 15, 12:10 pm, Maratonmannen
    <> wrote:
    > It was Vista.
    > I was a beta-tester from the beginning. And I always did run 64-bit, just to
    > see my all 4. :)
    >
    > --
    > Asus P5WDG2 WS Pro (i975X Express)
    > Core™ 2 Extreme X6800
    > RAPTOR 2x150 GB RAID 0
    > 4GB DDR2 800MHz
    > GeForce 8800GTX (162.18+165.01)
    > Enermax 1000W 75A@+12V
    > LAN 100/100
    > XP x64 dualboot Vista x64
    >
    > "Mark" wrote:
    > > Thanks!
    > > I'm assuming the two years ago wasn't Vista... :)

    >
    > > "Maratonmannen" wrote:

    >
    > > > My Vista Ultimate, Business and Windows Server 2008 x64 systems are all seing
    > > > my 4 GB RAM.
    > > > It has been this way since day 1, two years ago.
    > > > Intel chipsets (i955X and i975X), no memory remapping setting in BIOS.

    >
    > > > --
    > > > Asus P5WDG2 WS Pro (i975X Express)
    > > > Core™ 2 Extreme X6800
    > > > RAPTOR 2x150 GB RAID 0
    > > > 4GB DDR2 800MHz
    > > > GeForce 8800GTX (163.11+165.01)
    > > > Enermax 1000W 75A@+12V
    > > > LAN 100/100
    > > > XP x64 dualboot Vista x64

    >
    > > > "Mark" wrote:

    >
    > > > > I'm probably out of my league, but when did that ever stop someone from
    > > > > posting. (Yes, there is a question at the end of the post.)
    > > > > [Note: Also posted in General Discussion.]

    >
    > > > > Computers have three main buses:
    > > > > Control Bus
    > > > > Data Bus
    > > > > Address Bus

    >
    > > > > Control Bus is 16 bits wide and tells the address bus what method of
    > > > > communication is required (32-bit or 48-bit)for the device currently seeking
    > > > > to control the data bus.

    >
    > > > > Data Bus is 64-bits wide, but typically cannot find anything to talk to
    > > > > wider than 32-bits other than the main processor which for most systems is
    > > > > also working in 32-bit mode.

    >
    > > > > Address Bus is 48-bits wide and typically operates in one of two modes:
    > > > > 32-bit or 48-bit. This method of operation depends on the Control Bus'
    > > > > instructions. 32-bit for peripheral devices. 48-bit for the main processor.
    > > > > In theory, 48-bit could access 2^48 addresses. (65,536 * 4GB) But, those
    > > > > darned peripheral chips force the control bus to limit the address bus to
    > > > > 32-bit or 4GB.

    >
    > > > > Peripheral devices (video card, sound card, modem, etc.) are hard coded to
    > > > > work in 32-bit. If your OS is 64-bit, then the drivers must be in 64-bit to
    > > > > ensure information sent to the peripheral device is formatted in a manner it
    > > > > can understand. Information from the device must be padded to 64-bit. And the
    > > > > control bus must be told it is still a 32-bit device. If the device is
    > > > > actually a 64-bit device (extremely rare) then the control bus is told it is
    > > > > a 64-bit device and lets the address bus do it's thing.

    >
    > > > > But, 32-bit hardware changes how the address bus works. (Fixed with 64-bit
    > > > > drivers.) The upper 16 bits of the address bus become a means of identifying
    > > > > the device, mode of communication, etc. (essentially, paging mode for these
    > > > > devices to allow more than 4GB of memory to be addressed) and shift data
    > > > > transfer to a two iteration process (slowing things down.) Vendors understand
    > > > > this and design hardware to gain the speed of the processor by memory-mapping
    > > > > their hardware into RAM addresses so that the address bus does not shift to
    > > > > two step mode when sending or retrieving information to and from that device.
    > > > > This memory mapping reduces available RAM since the addresses cannot exist in
    > > > > duplicate.

    >
    > > > > Based on this (probably flawed logic), it does not appear to me that
    > > > > converting to 64-bit Vista will improve my memory situation unless I actually
    > > > > install more than 4GB of memory to get above the peripheral devices memory
    > > > > mapping "window." Until then, the memory mapping of the peripheral devices
    > > > > still eats the RAM between 3GB and 4GB.

    >
    > > > > Is this correct?
    > > > > Are 64-bit Vista users seeing 4 GB of RAM or the 3.2 GB "limit" with 4GB of
    > > > > RAM installed?


    As has been mentioned before but is worth repeating, some bios needs
    to do a memory remap to see all 4Gbytes. On my Nforce4, I need to do
    control-f1 just to see the remap option.
    , Aug 15, 2007
    #5
  6. =?Utf-8?B?TWFyaw==?= <> wrote in
    news::

    > I'm probably out of my league, but when did that ever stop someone
    > from posting. (Yes, there is a question at the end of the post.)
    > [Note: Also posted in General Discussion.]


    Not trying to pick on you, but please go take a digital logic class
    before someone that's willing to really rip you apart sees this. ;-)


    > Computers have three main buses:
    > Control Bus
    > Data Bus
    > Address Bus




    > Control Bus is 16 bits wide and tells the address bus what method of
    > communication is required (32-bit or 48-bit)for the device currently
    > seeking to control the data bus.
    >
    > Data Bus is 64-bits wide, but typically cannot find anything to talk
    > to wider than 32-bits other than the main processor which for most
    > systems is also working in 32-bit mode.


    Oops, you forgot the RAM. 99% of all work done by the CPU is with the
    RAM or Cache.


    > Address Bus is 48-bits wide and typically operates in one of two
    > modes: 32-bit or 48-bit. This method of operation depends on the
    > Control Bus' instructions. 32-bit for peripheral devices. 48-bit for
    > the main processor. In theory, 48-bit could access 2^48 addresses.
    > (65,536 * 4GB) But, those darned peripheral chips force the control
    > bus to limit the address bus to 32-bit or 4GB.


    Wrong, because the control bus knows when you are talking to a device or
    RAM. When you talk in 48bit mode, it can disable all those.


    > If your OS is 64-bit, then the drivers must
    > be in 64-bit to ensure information sent to the peripheral device is
    > formatted in a manner it can understand. Information from the device
    > must be padded to 64-bit. And the control bus must be told it is still
    > a 32-bit device. If the device is actually a 64-bit device (extremely
    > rare) then the control bus is told it is a 64-bit device and lets the
    > address bus do it's thing.


    This is why your OS needs to be 64bit, not the hardware. The DRIVERS
    control the devices, and could easily handle the 32/48 bit switching, if
    the programmers knew what they were doing. Problem is, most programmer
    are VERY lazy, or they would be doing hardware design, not software
    design. ;-)

    Also, most control devices are 8bit (with a few 16bit), not 32bit!


    --
    _______________________________________________
    / David Simpson \
    | |
    | http://www.nyx.net/~dsimpson |
    |We got to go to the crappy town where I'm a hero.|
    \_______________________________________________/
    David Simpson, Aug 15, 2007
    #6
  7. =?Utf-8?B?TWFyaw==?=

    Mark Guest

    I appreciate the corrections!
    (Didn't really forget the RAM, just thought of it as part of the main
    processor realizing it is more "directly" linked.)

    The 8-bit comment is a "bit" surprising.


    "David Simpson" <> wrote in message
    news:Xns998DA969958C3dsimpsonnyxnetmememe@216.196.97.131...
    > =?Utf-8?B?TWFyaw==?= <> wrote in
    > news::
    >
    >> I'm probably out of my league, but when did that ever stop someone
    >> from posting. (Yes, there is a question at the end of the post.)
    >> [Note: Also posted in General Discussion.]

    >
    > Not trying to pick on you, but please go take a digital logic class
    > before someone that's willing to really rip you apart sees this. ;-)
    >
    >
    >> Computers have three main buses:
    >> Control Bus
    >> Data Bus
    >> Address Bus

    >
    >
    >
    >> Control Bus is 16 bits wide and tells the address bus what method of
    >> communication is required (32-bit or 48-bit)for the device currently
    >> seeking to control the data bus.
    >>
    >> Data Bus is 64-bits wide, but typically cannot find anything to talk
    >> to wider than 32-bits other than the main processor which for most
    >> systems is also working in 32-bit mode.

    >
    > Oops, you forgot the RAM. 99% of all work done by the CPU is with the
    > RAM or Cache.
    >
    >
    >> Address Bus is 48-bits wide and typically operates in one of two
    >> modes: 32-bit or 48-bit. This method of operation depends on the
    >> Control Bus' instructions. 32-bit for peripheral devices. 48-bit for
    >> the main processor. In theory, 48-bit could access 2^48 addresses.
    >> (65,536 * 4GB) But, those darned peripheral chips force the control
    >> bus to limit the address bus to 32-bit or 4GB.

    >
    > Wrong, because the control bus knows when you are talking to a device or
    > RAM. When you talk in 48bit mode, it can disable all those.
    >
    >
    >> If your OS is 64-bit, then the drivers must
    >> be in 64-bit to ensure information sent to the peripheral device is
    >> formatted in a manner it can understand. Information from the device
    >> must be padded to 64-bit. And the control bus must be told it is still
    >> a 32-bit device. If the device is actually a 64-bit device (extremely
    >> rare) then the control bus is told it is a 64-bit device and lets the
    >> address bus do it's thing.

    >
    > This is why your OS needs to be 64bit, not the hardware. The DRIVERS
    > control the devices, and could easily handle the 32/48 bit switching, if
    > the programmers knew what they were doing. Problem is, most programmer
    > are VERY lazy, or they would be doing hardware design, not software
    > design. ;-)
    >
    > Also, most control devices are 8bit (with a few 16bit), not 32bit!
    >
    >
    > --
    > _______________________________________________
    > / David Simpson \
    > | |
    > | http://www.nyx.net/~dsimpson |
    > |We got to go to the crappy town where I'm a hero.|
    > \_______________________________________________/
    Mark, Aug 15, 2007
    #7
  8. I have to particularily thank you for this lesson, David. I knew I smelled
    'fish' but my background is old and muddy. I knew the BIOS is 8bit, but I
    wouldn't have thought of it in this context, I assume now that it is
    significant? (unless they went and changed that too. . .)


    Tony. . .
    Tony Sperling, Aug 16, 2007
    #8
  9. =?Utf-8?B?TWFyaw==?=

    Mark Guest

    Okay, you made me look it up!

    Most of the BIOS chips I looked at (pinouts) had 16-18 bit address buses
    and, yes, 8-bit data buses. Of course, it's not really fair to say that the
    BIOS is normally operating this way since it transfers itself to RAM and
    uses the main processor from that point to perform it's functions. (Never
    returning to the actual BIOS chip for help.) The BIOS on the various
    peripherals do much the same thing during initial boot. So while there is an
    initial flurry of 8-bit activity, it seems to subside rather quickly before
    the OS is actually loaded.

    Once past this point, there is mostly a mixture of 16-bit (few) and 32-bit
    (most) data streams from peripherals. (Of course age of computer and
    peripherals will determine this mix better.)

    I should have taken a refresher course. My TRS-80 knowledge is just a little
    out of date and just doesn't bridge the gap anymore. Thanks for not beating
    me up too much.



    "David Simpson" <> wrote in message
    news:Xns998DA969958C3dsimpsonnyxnetmememe@216.196.97.131...
    > =?Utf-8?B?TWFyaw==?= <> wrote in
    > news::
    >
    >> I'm probably out of my league, but when did that ever stop someone
    >> from posting. (Yes, there is a question at the end of the post.)
    >> [Note: Also posted in General Discussion.]

    >
    > Not trying to pick on you, but please go take a digital logic class
    > before someone that's willing to really rip you apart sees this. ;-)
    >
    >
    >> Computers have three main buses:
    >> Control Bus
    >> Data Bus
    >> Address Bus

    >
    >
    >
    >> Control Bus is 16 bits wide and tells the address bus what method of
    >> communication is required (32-bit or 48-bit)for the device currently
    >> seeking to control the data bus.
    >>
    >> Data Bus is 64-bits wide, but typically cannot find anything to talk
    >> to wider than 32-bits other than the main processor which for most
    >> systems is also working in 32-bit mode.

    >
    > Oops, you forgot the RAM. 99% of all work done by the CPU is with the
    > RAM or Cache.
    >
    >
    >> Address Bus is 48-bits wide and typically operates in one of two
    >> modes: 32-bit or 48-bit. This method of operation depends on the
    >> Control Bus' instructions. 32-bit for peripheral devices. 48-bit for
    >> the main processor. In theory, 48-bit could access 2^48 addresses.
    >> (65,536 * 4GB) But, those darned peripheral chips force the control
    >> bus to limit the address bus to 32-bit or 4GB.

    >
    > Wrong, because the control bus knows when you are talking to a device or
    > RAM. When you talk in 48bit mode, it can disable all those.
    >
    >
    >> If your OS is 64-bit, then the drivers must
    >> be in 64-bit to ensure information sent to the peripheral device is
    >> formatted in a manner it can understand. Information from the device
    >> must be padded to 64-bit. And the control bus must be told it is still
    >> a 32-bit device. If the device is actually a 64-bit device (extremely
    >> rare) then the control bus is told it is a 64-bit device and lets the
    >> address bus do it's thing.

    >
    > This is why your OS needs to be 64bit, not the hardware. The DRIVERS
    > control the devices, and could easily handle the 32/48 bit switching, if
    > the programmers knew what they were doing. Problem is, most programmer
    > are VERY lazy, or they would be doing hardware design, not software
    > design. ;-)
    >
    > Also, most control devices are 8bit (with a few 16bit), not 32bit!
    >
    >
    > --
    > _______________________________________________
    > / David Simpson \
    > | |
    > | http://www.nyx.net/~dsimpson |
    > |We got to go to the crappy town where I'm a hero.|
    > \_______________________________________________/
    Mark, Aug 16, 2007
    #9
  10. "Mark" <> wrote in news:#n9#Fx43HHA.4476
    @TK2MSFTNGP06.phx.gbl:

    > I appreciate the corrections!
    > (Didn't really forget the RAM, just thought of it as part of the main
    > processor realizing it is more "directly" linked.)
    >
    > The 8-bit comment is a "bit" surprising.


    I really wish I could explaine things in better detail. It really 99% an
    OS problem, and in a few cases, a 1% hardware problem. (some hardware
    designers are lazy)

    Most hardware still deals with 8 bits at a time. Sure the drivers or
    control regusters and buffers are 16, 32 or in the case of video cards even
    wider, it the drivers that control everything. M$ just decide that they
    wouldn't allow 32 bit driver in the 64 bit OS. Sure you want 64 bit when
    you talk to high speed stuff like a video card, but a keyboard? Even a
    scanner should be able to the slow down. They just didn't want to write it
    that way. From what I've heard, Apple is planning on you being able to use
    old 32 bit drivers in the 64 bit OS. That way you don't have to wait for
    print drivers that will never be released!


    --
    _______________________________________________
    / David Simpson \
    | |
    | http://www.nyx.net/~dsimpson |
    |We got to go to the crappy town where I'm a hero.|
    \_______________________________________________/
    David Simpson, Aug 16, 2007
    #10
  11. =?Utf-8?B?TWFyaw==?=

    Mark Guest

    Really appreciate the feedback!
    So much has changed... and apparently in some areas... not that much.

    "David Simpson" <> wrote in message
    news:Xns998E83FE446BBdsimpsonnyxnetmememe@216.196.97.131...
    > "Mark" <> wrote in news:#n9#Fx43HHA.4476
    > @TK2MSFTNGP06.phx.gbl:
    >
    >> I appreciate the corrections!
    >> (Didn't really forget the RAM, just thought of it as part of the main
    >> processor realizing it is more "directly" linked.)
    >>
    >> The 8-bit comment is a "bit" surprising.

    >
    > I really wish I could explaine things in better detail. It really 99% an
    > OS problem, and in a few cases, a 1% hardware problem. (some hardware
    > designers are lazy)
    >
    > Most hardware still deals with 8 bits at a time. Sure the drivers or
    > control regusters and buffers are 16, 32 or in the case of video cards
    > even
    > wider, it the drivers that control everything. M$ just decide that they
    > wouldn't allow 32 bit driver in the 64 bit OS. Sure you want 64 bit when
    > you talk to high speed stuff like a video card, but a keyboard? Even a
    > scanner should be able to the slow down. They just didn't want to write
    > it
    > that way. From what I've heard, Apple is planning on you being able to
    > use
    > old 32 bit drivers in the 64 bit OS. That way you don't have to wait for
    > print drivers that will never be released!
    >
    >
    > --
    > _______________________________________________
    > / David Simpson \
    > | |
    > | http://www.nyx.net/~dsimpson |
    > |We got to go to the crappy town where I'm a hero.|
    > \_______________________________________________/
    Mark, Aug 16, 2007
    #11
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