I recently installed Ubuntu 11.10 x86 on a new computer that has 2 x 4 GB RAM installed (8 GB total).

But when I go to the Ubuntu system monitor it only shows 3.4 GB of memory (and 8 GB swap). I also have a Windows 7 installed with dual boot on the same computer, and there it shows 8 GB RAM in "Control Panel > System". The BIOS also recognize the 8 GBs.

I thought this could be a problem of the x86 release, and I needed to use x64, but I just asked a friend that has the same computer with Ubuntu 11.04 x86 and he says the system monitor shows him 8 GB of RAM.

What could I try to get Ubuntu to recognize the 8 GB of RAM? I really don't even know where to start testing.

$ sudo dmidecode --type 17 | grep -E "Size|Form Factor|Memory Device|Type"[sudo] password for revered:

Memory Device

    Size: 4096 MB

    Form Factor: DIMM

    Type: Unknown

    Type Detail: None

Memory Device

    Size: 4096 MB

    Form Factor: DIMM

    Type: Unknown

    Type Detail: None

Memory Device

    Size: No Module Installed

    Form Factor: DIMM

    Type: Unknown

    Type Detail: None

Memory Device

    Size: No Module Installed

    Form Factor: DIMM

    Type: Unknown

    Type Detail: None



$ free

             total       used       free     shared    buffers     cached

Mem:       3608164     566356    3041808          0      36748     222304

-/+ buffers/cache:     307304    3300860

Swap:      8369148          0    8369148