How to Lift Ubuntu Linux Ram Limit

All 32-bit systems have a RAM limit of 3 GB. This limits the maximum amount of RAM a system running on a 32-bit Linux can support. So, even if you have more than 3 GB of ram installed, it will show only 3 GB.

There was a previous workaround which allowed us to use more than 3GB of ram in Linux by installing the server Kernel. This provided us with a kernel which had PAE enabled. This could also be done by recompiling the Linux kernel with PAE enabled. But, this is no longer possible now as the i386-server flavor of Linux is being dropped according to the Ubuntu Wiki.

Thankfully, instead many OEM’s have made a request for a 32-bit Ubuntu with PAE enabled. In response to this, Karmic Koala has options to use PAE. This has been possible due to the meta package linux-generic-pae, which has been added to the Karmic Koala build and allows us to enable PAE for the desktop version.

To enable more than 3 GB, enter this in a terminal. This command will install the PAE packages.

sudo apt-get install linux-generic-pae

Now after restarting the sytem, your Ubuntu should use the full RAM resource of your computer.

For more information on PAE, see the Wikipedia page here.

For more information on meta packages, see the Ubuntu help page here.

[ Via Web Upd8 ]

Published by

Chinmoy Kanjilal

Chinmoy Kanjilal is a FOSS enthusiast and evangelist. He is passionate about Android. Security exploits turn him on and he loves to tinker with computer networks. He rants occasionally at You can connect with him on Twitter @ckandroid.

  • I ran the command, and it was actually showing that it was already installed. My laptop is a Toshiba A100, with 4G of RAM, as confirmed by the startup status and config.

    However, when I check the status, it only shows 2.9G of RAM, not the 4G of RAM. Any idea why ?

    • The startup is independent of the OS. It is a low-level subsystem readying your system. It will detect anything you have as hardware, but the OS will not use it if it has no support.

  • Volnei

    Thanks a lot for posting this tip! Already installed the PAE-ENABLED Kernel and got my 4MB ram recognized in my 32-bit system. Using Karmic here.
    Your blog is very interesting and useful, thanks again!

  • Volnei

    Errr… 4GB of RAM, of course. Sorry for the mistake ;)

  • sudden death

    Gonna try installing PAE Kernel today!, have a home server Quad Xeon 3.0ghz with Hyperthreading for 8 Threads and 8 gigs of ECC Ram so wish me luck

    • Wow! Good luck. Share any performance difference. Make sure to run some benchmarks.