1. Welcome to TechPowerUp Forums, Guest! Please check out our forum guidelines for info related to our community.

The 32-bit/64-bit/2GB Per App/Not really 4GB RAM Limit Thing

Discussion in 'Motherboards & Memory' started by locutus, May 29, 2008.

  1. locutus New Member

    Joined:
    May 24, 2008
    Messages:
    8 (0.00/day)
    Thanks Received:
    2
    I'm trying to get a handle on the 32-bit/64-bit/2GB Per App/Not really 4GB RAM limit thing. Nice title huh? :)

    A 32-bit app is limited to 2GB in Win XP32 unless you use the /3GB /userva switches in the boot.ini file and the app was compiled with the /largeaddressaware switch. Then the app can use close to 3GB. This I'm sure is right because I found it on so many sites.

    A 32-bit app is limited to 2GB in Win XP64 (because XP64 is emulating XP32), unless you use the /3GB /userva switches in the boot.ini file and the app was compiled with the /largeaddressaware switch. Then the app can use 4GB. This I'm not sure about. According to one site I found, the app would have access to up to 4GB, but never more than 4GB. Is this right?

    If XP32 made use of PAE the way it was intended we would have access to 64GB (although each app would still be limited to 2GB), but XP sets the limit at 4GB even though PAE is enabled.
     
  2. CrackerJack

    CrackerJack

    Joined:
    Dec 13, 2007
    Messages:
    2,719 (1.04/day)
    Thanks Received:
    452
    Location:
    East TN
    Yeah nice title lol

    Your right on the memory usage. But using switch in xp64 won't always work. There not many 64-app out there anyway. The heaviest program I use is Adobe CS3, which is only a 32-bit app. But works awhole lot better x64 world. But in till CS4 comes out, I'm stuck with just using 2gb out of the 6gb that I have in my rig now. Even if you use a patch or edit the boot.inf, that's really only going effect windows itself.
     
  3. locutus New Member

    Joined:
    May 24, 2008
    Messages:
    8 (0.00/day)
    Thanks Received:
    2
    Do you mean using the switch with 64-bit apps? I wasn't talking about because with 64-bit apps you don't need the switch.

    So you have 6GB in your system and Adobe CS3 works better in X64 than in XP32? That's weird because when you run it, X64 should be running CS3 within an emulation of XP32. That's what MS calls WOW64. That means it should be limited to 2GB just the way it is in XP32.
     
  4. CrackerJack

    CrackerJack

    Joined:
    Dec 13, 2007
    Messages:
    2,719 (1.04/day)
    Thanks Received:
    452
    Location:
    East TN
    It's just more responsive than x32.
     
  5. OzzmanFloyd120

    OzzmanFloyd120

    Joined:
    Apr 3, 2008
    Messages:
    3,047 (1.22/day)
    Thanks Received:
    297
    Location:
    Pontaic Michigan
    I believe it, I've heard some places that the x86 emulation in vista is better than having a x86 OS in the first place.
     
  6. CrackerJack

    CrackerJack

    Joined:
    Dec 13, 2007
    Messages:
    2,719 (1.04/day)
    Thanks Received:
    452
    Location:
    East TN
    Well i've tested: XP Home SP2, XP Pro SP2 x64, Vista x86, Vista x64. Out of all these, Vista x64 runs 10 times better. More stable and responsive.
     
  7. Jizzler

    Jizzler

    Joined:
    Aug 10, 2007
    Messages:
    3,488 (1.28/day)
    Thanks Received:
    656
    Location:
    Geneva, FL, USA
    Took a high res poster-sized image with multiple layers, but I got memory usage over 2GB with both CS2 and CS3 :)
     
  8. OzzmanFloyd120

    OzzmanFloyd120

    Joined:
    Apr 3, 2008
    Messages:
    3,047 (1.22/day)
    Thanks Received:
    297
    Location:
    Pontaic Michigan
    Could that be because the image is eating 2gb of ram and then the amount that CS takes, or is it just the image?
     
  9. locutus New Member

    Joined:
    May 24, 2008
    Messages:
    8 (0.00/day)
    Thanks Received:
    2
    Do you agree that XP32 is faster than Vista32? I just read an article in PCWorld that says Vista is slower than XP Pro. Even with SP1 which is supposed to speed Vista up, it's still slower than XP Pro. That's all 32-bit. They didn't measure 64-bit OSs.

    Vista64 is much faster than XP64? How did you test them? Did you compare the performance in any games? I've heard Vista is very bloated.
     
  10. CrackerJack

    CrackerJack

    Joined:
    Dec 13, 2007
    Messages:
    2,719 (1.04/day)
    Thanks Received:
    452
    Location:
    East TN
    XP64 better used with games and benchmarks. But I was just saying CS3 and few other heavy programs run better on Vista x64.
     

Currently Active Users Viewing This Thread: 1 (0 members and 1 guest)

Share This Page