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

[ken]

On 07/22/2010 05:43 PM JohnS wrote:
> On Thu, 2010-07-22 at 17:33 -0400, ken wrote:
>> On 07/22/2010 02:39 PM Hakan Koseoglu wrote:
>>> JD,
>>> 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
>>> x86_64
>> I'm trying to catch up...
>>
>> Is the 737M cached (in the output above) what is reserved for bios or
>> chipset...?  and what is gained back through remapping?
> ---
> If you would look at my prior post you can actually see it as in whats
> used.  It is 2GB of ram on 12GB capability.
> 
> Run "dmesg | grep Memory" on your machine to see it.

What do you mean above in the three instances of "it"?  Don't know what
you're referring to.