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

Thu Jul 22 18:39:03 UTC 2010
Hakan Koseoglu <hakan at koseoglu.org>

On 22/07/10 10:25, John Doe wrote:
> I was wondering if anyone would know the cons of running a PAE kernel...?
> I have a 4GB pc and was wondering if it was worth going the PAE way to gain
> those exta 700MB...
You should use 64 bit if possible but if you're seeing 3.2GB, it's more 
likely that your motherboard is not capable (I have one of those here 
right now).

> In the past, I heard that these 700MB were normally reserved for bios or chipset
> stuff...
It still is, even with with 64 bit. If your motherboard supports 
remapping this memory with 64 bit you can use the whole 4GB. Otherwise 
you're limited to 3.2:

hakan at photon:~$ free -m
              total       used       free     shared    buffers     cached
Mem:          3262       1972       1290          0        103        737
-/+ buffers/cache:       1131       2131
Swap:         7812        308       7504
hakan at photon:~$ arch