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My OS is 32-bit Ubuntu 12.04. I have never intended to install PAE. But after recent change of my memory, it can detect 7.8 GB RAM.

In general, how can I find out if PAE has been enabled in Ubuntu? Thanks!

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PAE kernel is already default install in Ubuntu, don't know about Xubuntu or Lubuntu status about it. – xangua Dec 26 '13 at 3:22
is there a command to check that? – T... Dec 26 '13 at 3:24
up vote 2 down vote accepted

By definition, if you can see more then 3.2 Gb of RAM with a 32 bit kernel, pae is enabled.

To confirm this you can

grep --color=always pae /proc/cpuinfo

For additional information see

EDIT: Actually, that grep command only shows that your cpu is pae capable. You know it is enabled if you can see more then 3.2 Gb RAM. See the above link for further information.

To see if it is enabled in your kernel

grep CONFIG_HIGHMEM64G /boot/config-your-kernel

If PAE is enabled you will see


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