Possible Duplicate:
Why does Ubuntu only show 3GB of RAM?

System reports 2.6GiB, I have 8GB installed in the machine.

In previous versions when installing 32 bit versions the GRUB entry would mention "pae", physical address extension, on the list, but not with this.

Any chance I can get that set up correctly without doing a reinstall?

System details: i5 2500K on ASRock Z68M-ITX/HT

steven@steven-desktop:~$ uname -a
Linux steven-desktop 3.0.0-12-generic #20-Ubuntu SMP Fri Oct 7 14:50:42 UTC 2011 i686 i686 i386 GNU/Linux
steven@steven-desktop:~$ free -m
             total       used       free     shared    buffers     cached
Mem:          2688       1310       1378          0        113        562
-/+ buffers/cache:        633       2055
Swap:         3904          0       3904

marked as duplicate by Lekensteyn, Jorge Castro, Takkat, fossfreedom, Bruno Pereira Feb 13 '12 at 8:34

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • Out of curiosity, could you please post the output of uname -a when run in a terminal? That should tell us what kernel you're running. And why not also free -m while we're at it, which shows how much RAM the system thinks you have. – Lakritsbollar Feb 10 '12 at 18:14

Yeah, just sudo apt-get update and sudo apt-get install linux-generic-pae. This should solve it (after succesfull install & reboot).

  • I wonder why the installer didn't do this for me? Then again I did run the installer with the network unplugged (ethernet default driver has issues with my chipset) – Steven Lu Feb 10 '12 at 18:58
  • this explains it. the initial instalation usually takes care of downloading the pae kernel if you have min 4GB RAM and installing the 32 bit Ubuntu, but you were disconected :) – lone_ranger Feb 10 '12 at 19:04
  • Well that didn't go well. I get a black screen, but the monitor light is still green so it's a black screen signal. Computer responds to nothing other than Ctrl+Alt+Del which reboots it. You think I should try to get the pae version of the same kernel version? – Steven Lu Feb 10 '12 at 19:37
  • Okay. I loaded up 3.0.0-12-generic-pae since 3.0.0-15-generic-pae gave me a black screen. It works. I had to recompile the network driver, which was easy. free -m now shows 7983! Could somebody shed some light on why I might get a messed up system by going from -12 to -15? I have been able to update the kernel in the past without stuff failing like this. But I am definitely more hesitant to apply updates on Linux than I am for Windows these days, because I never know if something (or everything) is going to stop working. – Steven Lu Feb 10 '12 at 19:47

It should be easy to get the PAE kernel installed. Just search for it in Software Center, Synaptic, or use apt-get. It will take some time to download + install it, but on reboot you will have all your 8 GB :)

This is because when you install this kernel, the grub will also be updated and this kernel will be the one booted by default.

  • 1
    can I sudo apt-get install linux-generic-pae? Can't find anything matching the terms in software center, and I don't even think Synaptic is installed in this version. – Steven Lu Feb 10 '12 at 18:26
  • @StevenLu, yes, that's exactly what you should do. – psusi Feb 10 '12 at 18:45

Not the answer you're looking for? Browse other questions tagged or ask your own question.