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

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

  1. 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
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  2. 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
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  3. David J Taylor

    Ron Hunter Guest

    It depends on the OS settings, and what else you have running. There
    are programs that will let you monitor your 'free ram', but they are
    largely useless as many programs just grab all free memory, or a large
    percentage thereof to make their operations faster. If you regularly
    'page' to disk, then things slow down drastically, and you may need more
    ram. Things like photoediting take up a lot of ram, but I would think
    4GB would be more than enough for most users.
    Ron Hunter, Jan 28, 2006
  4. David J Taylor

    Ron Hunter Guest

    Since 'virtual memory' is really the free space on your HD, then should
    should have MUCH more than 1GB of virtual memory, or you badly need a
    larger HD!
    Ron Hunter, Jan 28, 2006
  5. David J Taylor

    Ron Hunter Guest

    Right-click on your 'my computer' icon, then select 'properties'. It
    will tell you how much system ram it can access.
    Ron Hunter, Jan 28, 2006
  6. 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
  7. 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
  8. Understand. Well, memory is so cheap that it's nothing more than pocket
    change unless you need several gigs of RAMBUS. At this point in time, since
    you are pretty much at the limitations of your 32-bit platform, you should
    just pack the 4GB in there and use the /3GB switch and enjoy your system
    till you upgrade your hardware to 64-bit. Good luck.

    Rita Ä Berkowitz, Jan 28, 2006
  9. Huh? I'm not even sure this is something I would even think of basing my
    upgrade decision on. What's in Win64 is more than adequate, why would you
    want a third party kludge that gives you a false sense of security?

    Rita Ä Berkowitz, Jan 28, 2006
  10. Been there and done that. It works great in 90% of the applications and is
    great advice, but it's not that hard to slam into the wall by running out of
    memory. I did this and found the tradeoff of letting Windows manage my
    pagefile more advantageous for my needs much better so I switched back.

    Rita Ä Berkowitz, Jan 28, 2006
  11. 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
  12. 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
  13. 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
  14. 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
  15. 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
  16. David J Taylor

    Al Dykes Guest

    But not with XP.
    Al Dykes, Jan 28, 2006
  17. 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
  18. 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
  19. David J Taylor

    Al Dykes Guest

    There is no such thing as "free memory" in a modern OS. The job of the
    OS is to make most effective use of all hardware resources. If the
    working set of you applications isn;t asking for the memory it gets
    used for buffers and file IO cache.
    Al Dykes, Jan 28, 2006
  20. Unfortunately, with Windows XP it has more impact than with VMS. In 1980
    I bought (for the company) one of the very first VAX-11/750s. I recall it
    had a whole megabyte of memory (at the time when 64K in your home-built PC
    was good going). I think the most memory I saw in a VAX was 128MB or
    possibly 256MB, with some of the early Alpha systems. A few MB for I/O
    space was nothing (at the top end of 4GB). Today, it seems that with
    video cards at 256MB, you loose that for each processor (or processor
    core), so 512MB of memory can be lost very easily.

    Just looked up my VMS Internals and Data Structures Manual - P0, P1, S0
    space - the top 1GB not for memory!

    David J Taylor, Jan 28, 2006
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