If you have 4GB, are you getting 4GB?

Discussion in 'Digital Cameras' started by David J Taylor, Jan 26, 2006.

  1. If you are fortunate enough to have 4GB of physical memory for your image
    editing with Windows XP, are you actually seeing 4GB?

    David J Taylor, Jan 26, 2006
    1. Advertisements

  2. Eh? Windows uses the physical memory it needs, then some more, and once
    it's run out it uses the disk as well.
    Hywel Jenkins, Jan 26, 2006
    1. Advertisements

  3. David J Taylor

    JohnR66 Guest

    To expand on this, even with the 3 GB switch set, each 32 bit application
    gets 2 GB of space max. So one app would have 2 GB and the other could have
    the remaining 1GB.

    If you put 4GB in a non server machine, it is important to use the switch or
    you are wasting memory as the OS never uses anywhere near 2GB in a

    Also, with 4GB, the chipset may use some address space and you will only get
    something like 3.4GB.
    JohnR66, Jan 27, 2006
  4. Thanks, John. That's the first on-topic answer I've seen.

    Is there any chipset (and/or graphics card) which allows Windows XP to see
    the full 4GB?

    David J Taylor, Jan 27, 2006
  5. OK, I mean "does Windows report all the 4GB of physical memory as being
    available to the operating system".

    David J Taylor, Jan 27, 2006
  6. David J Taylor

    ASAAR Guest

    Do you really think that David is talking about secondary storage
    instead of 4GB of RAM? You must have missed replies from Rita,
    JohnR66 and then David's followup. They're all in the thread,
    unless your newsreader messed up (it happens sometimes).
    ASAAR, Jan 27, 2006
  7. The "seeing less than the installed 4GB" issue is also present with 64-bit

    David J Taylor, Jan 27, 2006
  8. Rita,

    Yes, that is an alternative OS, which will support 4GB. However, my
    question was about Windows XP as I don't yet wish to move to Win64,
    although that will most likely be my next OS upgrade.

    I am dealing with some quite large images - 130Mpix - which take up some
    400MB of memory each. Coupling with this with doing software development,
    plus running a 500MB+ production system, is taxing my current 1GB system

    It seems that with Win32 today's systems don't give you access to all of
    the 4GB physical memory which many motherboards will allow, and this fact
    doesn't seem to be common knowledge.

    David J Taylor, Jan 27, 2006
  9. Well, it's a case at the moment of being limited to 1GB of memory on this
    4-year old Dell but often running a process which takes around 1GB of
    memory with all the other stuff still running (which takes nearly 1GB in
    itself). So do I upgrade to 2GB, 3GB or 4GB. I chose 4GB knowing that
    Win64 will support it, when I do upgrade.

    I don't think the Windows XP "can't use all of 4GB" limitation is that
    well known - XP is advertised as supporting 4GB and it was only with the
    subsequent release of SP2 with the DEP anti-malicious-code feature, and
    processors which supported it, that the "3GB" limit sems to have appeared.

    David J Taylor, Jan 28, 2006
  10. Yes, a further PC would be a good idea, but physical space and network
    connections are limited!

    2GB per process is [currently] fine. That allows the manipulation of my
    130MPix images. Yes, I know about the /3GB switch if needed (and I wrote
    my software to use it).

    Just as soon as Win64 supports my preferred anti-virus and firewall
    software I'll be off! I already have the CD.

    David J Taylor, Jan 28, 2006
  11. Ron Hunter wrote:
    Thanks, Ron.

    I know about that technique, but I don't have the actual PC in front of me
    just yet. Oh, and I don't have a "My computer" icon.

    On my existing PC, the 1GB of physical memory is reported as 1GB.
    However, a 4GB system reports less than 4GB - about 3.2GB. Hence my
    original question. I have had at least one other report confirming this
    behaviour, and there is a Microsoft article about it as well:


    David J Taylor, Jan 28, 2006
  12. No there could be another informed choice. Once can fix the size of the
    swap drive. That way you take Windoze out of the picture from wasting time
    and resources by "managing" it. set it 1.5 -2x your physical memory as a
    Ed Ruf (REPLY to E-MAIL IN SIG!), Jan 28, 2006
  13. Thanks, Rita. That is exactly what I have decided to do, and just leave
    the 4GB. The shop offered the option at 3GB at a reduced cost, but it
    seems penny pinching.

    David J Taylor, Jan 28, 2006
  14. Rita,

    Are you saying that there's no need for any 3rd party firewall and
    anti-virus software in Win64?

    David J Taylor, Jan 28, 2006
  15. I don't understand why you wouldn't then just set a higher fixed limit.
    Disk space is cheap and if you need it do it. Then you don't have to deal
    with automatic resizing and defragging that happens when you least expect
    it. Best kept on a partition separate from the one with the OS as well,
    Ed Ruf (REPLY to E-MAIL IN SIG!), Jan 28, 2006
  16. David J Taylor

    Al Dykes Guest

    The max size of any single process (or data structure) is 2GB in a 32
    bit system, and the pagefile gets used when total of all process
    Working Sets[1] exceeds the physical memory, limited to 3GB on a 32
    bit windows system. This is the 5 cent explanation.

    here's is a new Adobe tech note for CS2 that covers all current 32 and
    64 bit operating systems and 32 and 64 bit iron, as wall as workdisk


    [1] http://en.wikipedia.org/wiki/Working_set
    Al Dykes, Jan 28, 2006
  17. David J Taylor

    Al Dykes Guest


    The hack of using the upper part of the virtual address sapce for the
    operating system isn't unique to Windows. VMS did it right from the
    start, in 1978(?). IBM OS/360 did something similar in the 60s but I
    feel my memory dimmer, dimmer.......
    Al Dykes, Jan 28, 2006
  18. David J Taylor

    Al Dykes Guest

    But not with XP.
    Al Dykes, Jan 28, 2006
  19. David J Taylor

    Al Dykes Guest

    Buy a 64 bit PC for PS, but read your email and browse the internet
    porn sites on 32 bit XP running in a Virtual machine [1]. It will run
    your AV software and firewall in 32 bits. Any old DSL router/NAT box
    found in a dumpster will give you a physical brick wall firewall.

    If you don't use the 64 bit browser and are behind a physical firewall
    you're really safe.

    [1] VMWare or MS Virtual PC.
    Al Dykes, Jan 28, 2006
  20. David J Taylor

    Al Dykes Guest

    Virtual page management is a fundamental part of the Windows kernal.
    You can't make it go away. The type and number of applications you
    run determines how much physical memory needed, and if you don't have
    enough, some not-recently-used memory gets written to disk. this is
    called paging. Excess disk space doesn't help anything.

    The size of the page file, itself, doen't have any performance impact.
    It's the writing and reading of pages, measured in pages/sec, that
    does. Ths cost is in CPU cycles and context switches in addition to
    wallclock time and disk contention.

    perfmon.exe will tell you how many pages/sec you are reading and
    writing to pagefile. If, while you watching the windows hourglass,
    perfmon shows nearly zero pagefile IO activity then adding memory to
    you machine won't speed up your task.
    Al Dykes, Jan 28, 2006
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.