[ltp] X60s 4 GB RAM PAE only 3 recognized (64 Bit)

birger linux-thinkpad@linux-thinkpad.org
Thu, 13 Nov 2014 13:53:28 +0100

32bit addressing can only see 4GB RAM.
Some 32bit intel processors have an extension called PAE that enables a
32bit processor to address far more memory. To use this you need a PAE
kernel. A PAE kernel will fail if you try to boot it on a non-PAE

In your place I would upgrade to 64bit linux. The linux kernel handles
memory more efficiently in the 64bit kernel if you have more than 1GB
RAM. You can still run 32bit versions of applications if you want to do

Two of my children have X60s with 5GB RAM, SSD and 64-bit fedora. :-)

On Thu, 2014-11-13 at 09:41 +0100, Uwe Brauer wrote:
> Hello
> I bought my X60s with 500 MG of RAM, upgraded to 2.5, which was not
> recognized till I installed a PAE enabled kernel for my 32 bit Kubuntu.
> Now I upgraded again to 4 GB RAM, but even with PAE enabled only 3 are
> recognized. 
> Would it help to upgrade to a 64 bit version of Ubuntu?
> On my X200s the 4 GB RAM are recognized via PAE, so I presume the answer
> would be no, but I don't really understand the differences between PAE
> and 64 in all details.
> Thanks 
> Uwe Brauer