PAE not working

**JamesStewy** · September 17th, 2012

Hi,

I am having trouble using PAE on Ubuntu Server 12.04 LTS 32bit. I recently upgraded from 4 to 8gb of RAM but PAE doesn't appear to have picked this up.

When I run

Code:

grep --color=always -i PAE /proc/cpuinfo

I get pae in the list.

When I run

Code:

dmidecode | grep Size | grep MB

Installed Size is 3825 but the Maximum Total Memory Size: 8192 MB.

When I check the BIOS it says there is 8192 MB available. The computer manual also says and the computer supports that amount.

I have followed everything I can find on the internet (including this https://help.ubuntu.com/community/EnablingPAE) and nothing is working.

My Computer is a Toshiba Portege M750 bought in 2009. It has an Intel Centrino Core 2 Duo processor. The RAM I bought doesn't appear to have a brand listed but this is where I got it http://www.ramcity.com.au/product/KI...200-8G-021.htm. It's specs are exactly the same as my old RAM except it is twice as big.

Thanks,

JamesStewy

**oldfred** · September 17th, 2012

Linus does not like PAE or 32 bit. Or you do not get what you think you might be getting:
http://cl4ssic4l.wordpress.com/2011/...lds-about-pae/

http://ubuntuforums.org/showthread.php?t=2028717
Essentially says if you can use the 64bit kernel you should.April 2011
http://www.phoronix.com/scan.php?pag...ty_pae64&num=1
https://help.ubuntu.com/community/32bit_and_64bit
Ubuntu 32-bit, 32-bit PAE, 64-bit Kernel Benchmarks Dec 2009
http://www.phoronix.com/scan.php?pag...u_32_pae&num=1

**JamesStewy** · September 17th, 2012

When I went to the downloads page for Ubuntu server it seamed like the 64bit version only worked on AMD processors. My laptop has an Intel. Am I missing something?

**oldfred** · September 17th, 2012

It is all the same.
http://en.wikipedia.org/wiki/X86-64

From the python page:
The binaries for AMD64 will also work on processors that implement the Intel 64 architecture (formerly EM64T), i.e. the architecture that Microsoft calls x64, and AMD called x86-64 before calling it AMD64.

They will not work on Intel Itanium Processors (formerly IA-64). These are limited production chips, used now for heavy duty servers running Unix.

**JamesStewy** · September 17th, 2012

Thanks a lot. I know this is getting a bit of topic now but is there a way that I can upgrade to 64bit without losing my programs, settings and files (especially for my website). Thanks again.