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Thread: 4GT setting

  1. #1
    Join Date
    Feb 2002
    Norwood, MA

    Unanswered: 4GT setting

    Hi all,

    Oracle 8.1.6, Windows 2000 Advanced Server, 4GB Ram.

    I'm trying to get a Windows 2000 Advanced Server machine with 4GB ram running Oracle 8i to take advantage of the 3GB ram available to Oracle. I am getting conflicting points of view regarding how to get this to work.

    On this 4GB machine, I think that all I need to do is set the /3GB flag in the boot.ini file and a 'normal' Oracle installation should take advantage of the 3GB memory allocation, as per this from Oracle:

    4GB RAM Tuning (4GT) Support

    Windows NT Server v4.0 Enterprise Edition includes a feature called 4GB RAM Tuning (4GT). This feature allows memory-intensive applications running on Windows NT Server Enterprise Edition to access up to 3GB of memory as opposed to the standard 2GB in previous versions of the operating system. The obvious benefit to Oracle8i is that 50% more memory becomes available for database use, which can increase SGA sizes or connection counts. All Oracle database server releases since 7.3.4 have supported this feature with no modifications necessary to a standard Oracle installation. The only configuration change required is to ensure that the /3GB flag is used in Windows' boot.ini file. This feature is also supported in Windows 2000.

    One of my colleagues seems to think we need to use the AWE_WINDOW_MEMORY registry key, but it seems to me that is only used if you want to use more than 3GB for Oracle, and you have more than 4GB of ram.

    Your help and experience is greatly appreciated.

    We do plan on adding an additional 4GB of ram in the near future, so if you could also comment on how to use the AWE_WINDOW_MEMORY registry setting that would be great.


  2. #2
    Join Date
    Apr 2001
    I don't know a lot about Windows administration ... seems like the 1 setting in boot.ini would be enough?

    But anyway, only setting this option will not cause Oracle to use the memory, you should also adjust the SGA parameters.
    (block_buffers, shared_pool_size, java_pool_size, sort_area_size etc..)

    Ruud Schilders
    Oracle DBA
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  3. #3
    Join Date
    Feb 2001
    NC, USA
    I've got a whitepaper from Oracle on this at work. I'll post it tomorrow. I'm pretty sure ruud is correct about windows 2000 though. It's only NT Enterprise that you have to fiddle with to get it to use 4GB.

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