1. Welcome Guest! In order to create a new topic or reply to an existing one, you must register first. It is easy and free. Click here to sign up now!.
    Dismiss Notice

32-bit and 64-bit Vista RAM limit?

Discussion in 'Windows Vista' started by Karmic Koala, May 28, 2009.

  1. Karmic Koala

    Karmic Koala Guest

    I have this question that what is the RAM limit with vista 32-bit and
    64-bit?

    I've heard that it is 3,2 GB but I've also heard that it would be 4,0GB
    (because 2^32 = 4.294.967.296. But then 64-bit systems could use over 18
    exabytes of RAM, because 2^64 = 18.446.744.073.709.551.616? Isn't that a
    little too much o_O).

    I've also heard that Vista with SP1 ´recognizes´ 4GB of RAM (earlier
    windows reputedly recognized only 3GB of RAM so does this mean that from
    Vista SP1 windowses *recognize* that 4th GB of RAM but can't *use* it?).


    --
    Karmic Koala
     
  2. Ex_Brit

    Ex_Brit Guest

    Basically 4gb for x86 vs 128gb for x64, there's a good article here
    about it (takes a while to load) '32-bit Windows Vista vs. 64-bit
    Windows Vista - Vs. system memory - Softpedia'
    (http:/ ews.softpedia.com ews/32-bit-Windows-Vista-vs-64-bit-Windows-Vista-64312.shtml).
    I have 4gb on my 32-bit systems and all of them use approximately
    3.33gb of it with my video card taking up some of that. As you said,
    Vista does see 4gb but can't use it all. But then the definition of
    "see" and "use" gets rather complicated.

    You'll read in that article that it's the design of the operating
    systems that effects it.


    --
    Ex_Brit

    ::*-Peter-*::
    Toronto, Canada
    XP Pro SP3, Vista Ultimate SP2, Windows 7 RC
    P4 HT @ 3.0ghz, 4gb DDR, 700gb HDD
     
  3. Jane C

    Jane C Guest

    Karmic Koala wrote:
    > I have this question that what is the RAM limit with vista 32-bit and
    > 64-bit?
    >
    > I've heard that it is 3,2 GB but I've also heard that it would be 4,0GB
    > (because 2^32 = 4.294.967.296. But then 64-bit systems could use over 18
    > exabytes of RAM, because 2^64 = 18.446.744.073.709.551.616? Isn't that a
    > little too much o_O).
    >
    > I've also heard that Vista with SP1 ´recognizes´ 4GB of RAM (earlier
    > windows reputedly recognized only 3GB of RAM so does this mean that from
    > Vista SP1 windowses *recognize* that 4th GB of RAM but can't *use* it?).
    >
    >



    --
    Jane, not plain ;) 64 bit enabled :)
    Batteries not included. Braincell on vacation ;-)
    MVP - Windows Desktop Experience 2007-2009
     
  4. Jane C

    Jane C Guest

    Karmic Koala wrote:
    > I have this question that what is the RAM limit with vista 32-bit and
    > 64-bit?
    >
    > I've heard that it is 3,2 GB but I've also heard that it would be 4,0GB
    > (because 2^32 = 4.294.967.296. But then 64-bit systems could use over 18
    > exabytes of RAM, because 2^64 = 18.446.744.073.709.551.616? Isn't that a
    > little too much o_O).
    >
    > I've also heard that Vista with SP1 ´recognizes´ 4GB of RAM (earlier
    > windows reputedly recognized only 3GB of RAM so does this mean that from
    > Vista SP1 windowses *recognize* that 4th GB of RAM but can't *use* it?).
    >
    >

    http://msdn.microsoft.com/en-us/library/aa366778.aspx

    --
    Jane, not plain ;) 64 bit enabled :)
    Batteries not included. Braincell on vacation ;-)
    MVP - Windows Desktop Experience 2007-2009
     
  5. "Karmic Koala" <guest@unknown-email.com> wrote in message
    news:9c1054cdb881771c783b6230a3e5017c@nntp-gateway.com...
    >
    > I have this question that what is the RAM limit with vista 32-bit and
    > 64-bit?
    >
    > I've heard that it is 3,2 GB but I've also heard that it would be 4,0GB
    > (because 2^32 = 4.294.967.296. But then 64-bit systems could use over 18
    > exabytes of RAM, because 2^64 = 18.446.744.073.709.551.616? Isn't that a
    > little too much o_O).
    >
    > I've also heard that Vista with SP1 ´recognizes´ 4GB of RAM (earlier
    > windows reputedly recognized only 3GB of RAM so does this mean that from
    > Vista SP1 windowses *recognize* that 4th GB of RAM but can't *use* it?).
    >
    >
    > --
    > Karmic Koala



    32bit Vista will report 4gb, but still only use 3gb or thereabouts..

    64bit Vista can see and use between 8gb and way more depending on Vista
    version..

    --

    Mike Hall - MVP Windows Experience
    http://msmvps.com/blogs/mikehall/
     
  6. H Brown

    H Brown Guest

    Go to the link below to learn the answer to your question.
    http://support.microsoft.com/kb/929605

    H Brown
    "Karmic Koala" <guest@unknown-email.com> wrote in message
    news:9c1054cdb881771c783b6230a3e5017c@nntp-gateway.com...
    >
    > I have this question that what is the RAM limit with vista 32-bit and
    > 64-bit?
    >
    > I've heard that it is 3,2 GB but I've also heard that it would be 4,0GB
    > (because 2^32 = 4.294.967.296. But then 64-bit systems could use over 18
    > exabytes of RAM, because 2^64 = 18.446.744.073.709.551.616? Isn't that a
    > little too much o_O).
    >
    > I've also heard that Vista with SP1 ´recognizes´ 4GB of RAM (earlier
    > windows reputedly recognized only 3GB of RAM so does this mean that from
    > Vista SP1 windowses *recognize* that 4th GB of RAM but can't *use* it?).
    >
    >
    > --
    > Karmic Koala
     
  7. Tim Slattery

    Tim Slattery Guest

    Karmic Koala <guest@unknown-email.com> wrote:

    >
    >I have this question that what is the RAM limit with vista 32-bit and
    >64-bit?
    >
    >I've heard that it is 3,2 GB but I've also heard that it would be 4,0GB
    >(because 2^32 = 4.294.967.296. But then 64-bit systems could use over 18
    >exabytes of RAM, because 2^64 = 18.446.744.073.709.551.616? Isn't that a
    >little too much o_O).


    32-bit Vista has an address space of 4,294,967,296 bytes, as you
    calculated. Some of that has to be used for BIOS, Video RAM and a few
    other things, so you can actually use only 3.2 - 3.5 GB of RAM. See
    http://members.cox.net/slatteryt/RAM.html

    You also calculated the maximum possible address space for a 64-bit
    machine. None of Microsoft's 64-bit operating systems implement a fill
    64-bit address space. 64-bit Vista Home Basic will handle 8GB, Home
    Premium 16GB, and the other versions will take 128GB.

    --
    Tim Slattery
    MS MVP(Shell/User)
    Slattery_T@bls.gov
    http://members.cox.net/slatteryt
     
  8. R. C. White

    R. C. White Guest

    Hi, Koala.

    > *recognize* that 4th GB of RAM but can't *use* it?).


    Vista x86 can use all the 4 GB of RAM. But some of that use is for video
    RAM, drivers and other functions that you have no control over, leaving
    less - typically about 3.2 GB but variable depending on YOUR hardware - for
    you to decide how to use.

    Suppose your local post office has 4,096 mailboxes available, but the PO
    reserves 800 of those boxes for its own use. If there are only 1,000 mail
    patrons in town, then there is no shortage and everybody gets their own
    mailbox. When the town grows to 2,000 or even 3,000, there is still no
    problem. But when another thousand patrons arrive, only about 200 will get
    mailboxes. The other 800 boxes are there and they are not being wasted.
    They are already in use (or reserved for something important).

    The full 4 GB is being used, but you don't get to specify how some of it is
    being used.

    Vista SP1 did change the way the 4 GB is being reported to the user, but did
    not change anything behind the curtain.

    RC
    --
    R. C. White, CPA
    San Marcos, TX
    rc@grandecom.net
    Microsoft Windows MVP
    Windows Live Mail 2009 (14.0.8064.0206) in Win7 Ultimate x64 RC 7100

    "Karmic Koala" <guest@unknown-email.com> wrote in message
    news:9c1054cdb881771c783b6230a3e5017c@nntp-gateway.com...
    >
    > I have this question that what is the RAM limit with vista 32-bit and
    > 64-bit?
    >
    > I've heard that it is 3,2 GB but I've also heard that it would be 4,0GB
    > (because 2^32 = 4.294.967.296. But then 64-bit systems could use over 18
    > exabytes of RAM, because 2^64 = 18.446.744.073.709.551.616? Isn't that a
    > little too much o_O).
    >
    > I've also heard that Vista with SP1 ´recognizes´ 4GB of RAM (earlier
    > windows reputedly recognized only 3GB of RAM so does this mean that from
    > Vista SP1 windowses *recognize* that 4th GB of RAM but can't *use* it?).
    >
    >
    > --
    > Karmic Koala
     
  9. Ian D

    Ian D Guest

    "R. C. White" <rc@grandecom.net> wrote in message
    news:eypCuM73JHA.1092@TK2MSFTNGP06.phx.gbl...
    > Hi, Koala.
    >
    >> *recognize* that 4th GB of RAM but can't *use* it?).

    >
    > Vista x86 can use all the 4 GB of RAM. But some of that use is for video
    > RAM, drivers and other functions that you have no control over, leaving
    > less - typically about 3.2 GB but variable depending on YOUR hardware -
    > for you to decide how to use.
    >
    > Suppose your local post office has 4,096 mailboxes available, but the PO
    > reserves 800 of those boxes for its own use. If there are only 1,000 mail
    > patrons in town, then there is no shortage and everybody gets their own
    > mailbox. When the town grows to 2,000 or even 3,000, there is still no
    > problem. But when another thousand patrons arrive, only about 200 will
    > get mailboxes. The other 800 boxes are there and they are not being
    > wasted. They are already in use (or reserved for something important).
    >
    > The full 4 GB is being used, but you don't get to specify how some of it
    > is being used.
    >
    > Vista SP1 did change the way the 4 GB is being reported to the user, but
    > did not change anything behind the curtain.
    >
    > RC
    > --
    > R. C. White, CPA
    > San Marcos, TX
    > rc@grandecom.net
    > Microsoft Windows MVP
    > Windows Live Mail 2009 (14.0.8064.0206) in Win7 Ultimate x64 RC 7100
    >


    That's an excellent analogy of 32 bit memory mapping. I've used it
    myself, but had the boxes reserved for large volume mail receivers
    rather than the PO, itself.

    What's often overlooked in 32 bit memory map explanations is that
    the 4GB space is divided, with 2GB allotted for applications, and
    2GB for the OS. Also, most 32 bit apps can't use more than 2GB
    of memory. In order for 32 bit apps to use more than 2GB, (4GB
    is the maximum), two conditions must be met. The application
    has to be large address aware, and run on 64 bit Vista, or the
    "set userva" setting must be applied to the Vista "bootmgr",
    (Boot Manager), file. A safe value for userva is 2700, which,
    in your example above, would allot 2700MB to applications,
    500MB to Vista, and 800 to hardware resources. This can also
    be applied to XP by adding "/3GB /userva=2700" to the boot
    line in the boot.ini file. If hardware used more than, or less
    than, 800MB, the userva value would be modified accordingly.
     
  10. John

    John Guest

    Even though Vista 64 may be able to handle more than 4 gb, be sure your
    computer chipset can handle the ram.

    "Karmic Koala" <guest@unknown-email.com> wrote in message
    news:9c1054cdb881771c783b6230a3e5017c@nntp-gateway.com...
    >
    > I have this question that what is the RAM limit with vista 32-bit and
    > 64-bit?
    >
    > I've heard that it is 3,2 GB but I've also heard that it would be 4,0GB
    > (because 2^32 = 4.294.967.296. But then 64-bit systems could use over 18
    > exabytes of RAM, because 2^64 = 18.446.744.073.709.551.616? Isn't that a
    > little too much o_O).
    >
    > I've also heard that Vista with SP1 ´recognizes´ 4GB of RAM (earlier
    > windows reputedly recognized only 3GB of RAM so does this mean that from
    > Vista SP1 windowses *recognize* that 4th GB of RAM but can't *use* it?).
    >
    >
    > --
    > Karmic Koala
     
  11. Tim Slattery

    Tim Slattery Guest

    "Ian D" <taurus@nowhere.com> wrote:


    >What's often overlooked in 32 bit memory map explanations is that
    >the 4GB space is divided, with 2GB allotted for applications, and
    >2GB for the OS.


    No, you're confusing physical and virtual memory. Each process running
    in Vista (or XP or ...) is allocated a 4GB virtual memory space
    (assuming you're on a 32-bit machine. I'm not sure how big the virtual
    space is on a 64-bit machine). 2GB of that virtual space is reserved
    for the OS. There will be *many* virtual spaces existing at any one
    time. The virtual storage system keeps pieces of all of them in
    physical RAM all the time, and other pieces in the swap file. It uses
    various techniques to try to make sure that the bit that's needed is
    in physical RAM when it's needed. But there's no OS vs application
    division in physical RAM.

    --
    Tim Slattery
    MS MVP(Shell/User)
    Slattery_T@bls.gov
    http://members.cox.net/slatteryt
     
  12. Ian D

    Ian D Guest

    "Tim Slattery" <Slattery_T@bls.gov> wrote in message
    news:99nv159aom0p2bp202fotlovdsqj9ql8dc@4ax.com...
    > "Ian D" <taurus@nowhere.com> wrote:
    >
    >
    >>What's often overlooked in 32 bit memory map explanations is that
    >>the 4GB space is divided, with 2GB allotted for applications, and
    >>2GB for the OS.

    >
    > No, you're confusing physical and virtual memory. Each process running
    > in Vista (or XP or ...) is allocated a 4GB virtual memory space
    > (assuming you're on a 32-bit machine. I'm not sure how big the virtual
    > space is on a 64-bit machine). 2GB of that virtual space is reserved
    > for the OS. There will be *many* virtual spaces existing at any one
    > time. The virtual storage system keeps pieces of all of them in
    > physical RAM all the time, and other pieces in the swap file. It uses
    > various techniques to try to make sure that the bit that's needed is
    > in physical RAM when it's needed. But there's no OS vs application
    > division in physical RAM.
    >
    > --
    > Tim Slattery
    > MS MVP(Shell/User)
    > Slattery_T@bls.gov
    > http://members.cox.net/slatteryt


    I wasn't talking about RAM, but memory space in a simplified
    manner. Yes, I know that each application has it's own 4GB of
    virtual address space, and that space is mapped to RAM as
    required. The point is that, if an application can't use more than
    2GB of addressing space, it obviously does not have access
    to more than 2GB of physical memory. MS itself says that
    increasing application address space via /3GB and userva i
    ncreases access to physical memory. This, of course, refers to
    systems running 32 bit Windows, with 4GB of RAM.

    One application that illustrates this is MS Flight Simulator X.
    If the fsx.exe file exceeds about 1800MB when running FSX,
    an out of memory error occurs, and FSX terminates. With
    FXS SP1, MS made FSX large address aware. Running
    FSX SP1 in XP with "/3GB /userva=", or in 32 bit Vista
    with "set userva", or in 64 bit Vista, the fsx.exe file can exceed
    2GB with no issues. In 64 bit Vista with more than 4GB of
    RAM, FSX is able to access a full 4GB. I have found that
    Photoshop Elements 6 is also large address aware.
     

Share This Page