[CentOS] To PAE or not to PAE...

Thu Jul 22 22:17:04 UTC 2010
Hakan Koseoglu <hakan at koseoglu.org>

On 22/07/10 22:33, ken wrote:

 > Is the 737M cached (in the output above) what is reserved for bios or
> chipset...?  and what is gained back through remapping?
Nope, it simply means even if I had 2GB RAM, there'd be plenty I'm not 
using for anything but cache - I don't do much on this laptop but 
browsing these days :)

What we are suffering from is explained neatly here: 
http://en.wikipedia.org/wiki/PCI_hole

Simply put, if the BIOS+chipset does not support mapping these reserved 
areas to higher addresses this memory is lost to us.

My Dell Inspiron 9400 is about 3+ years old now. More recent hardware 
have the necessary bits and pieces so that you can see all 4GB and use 
it with 64 bit or 32 bit + PAE. Server chipsets had this kind of support 
even earlier. Unfortunately for mine, Dell decided to only support 3GB.