Results 1 to 7 of 7

Thread: RAM size mismatch

  1. #1
    Join Date
    Jan 2012
    Beans
    106

    RAM size mismatch

    I installed Ubuntu 11.10 in January on my IBM ThinkCentre P51 with 2GB RAM with dual-boot option co-exist with Windows XP Pro. At the time Ubuntu showed 2GB RAM in the System Monitor.

    I added two more 1GB DDR RAM modules to the PC box, making it a total of 4GB RAM. In Windows XP Pro it shows 4.01GB, but in Ubuntu the System Monitor reports 3.6GB.

    Why the mismatch of the total RAM size?

  2. #2
    Join Date
    Feb 2009
    Location
    Dallas, TX
    Beans
    7,743
    Distro
    Ubuntu 16.04 Xenial Xerus

    Re: RAM size mismatch

    Hi chenxinghao.

    My first guess is that you are running the 32bit version and using the normal kernel. There is a an extension called 'pae' that will allow you to see the 4Gb (well, minus what low lever drivers, and graphic card use)

    Could you post the result of this command?
    Code:
    uname -a
    Regards.

  3. #3
    Join Date
    Jan 2012
    Beans
    106

    Re: RAM size mismatch

    Here is the output in Terminal:

    ~$ uname -a
    Linux MyUbuntuSandBox 3.0.0-17-generic #30-Ubuntu SMP Thu Mar 8 17:34:21 UTC 2012 i686 i686 i386 GNU/Linux
    ~$

  4. #4
    Join Date
    Feb 2009
    Location
    Dallas, TX
    Beans
    7,743
    Distro
    Ubuntu 16.04 Xenial Xerus

    Re: RAM size mismatch

    There it is.

    To install the pae extension:
    Code:
    sudo apt-get install linux-generic-pae
    Then reboot.

    Then you should see almost all 4Gb of RAM. For example in my case I see 3956Mb.

    Regards.

  5. #5
    Join Date
    Jan 2012
    Beans
    106

    Re: RAM size mismatch

    What does this pae do?

    I have GNU C/C++ compiler installed, as well as a few other applications (GNU emacs and VLC, etc.). Would this pae run into conflict with these applications?

  6. #6
    Join Date
    Oct 2005
    Location
    Syracuse, NY
    Beans
    659
    Distro
    Ubuntu 11.10 Oneiric Ocelot

    Re: RAM size mismatch

    PAE just allows 32-bit kernels to access 4GB's of RAM and higher... Your install of Ubuntu still may not show more than 3.6GB's, as part of your RAM is taken up for graphics memory automatically. Windows because it's consumer orientated takes this into account and shows the full # so people don't get all nosey and ask questions. **cough cough**

  7. #7
    Join Date
    Jan 2012
    Beans
    106

    Re: RAM size mismatch

    Many thanks.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •