[geeks] Greater than 4GB swapfile on XP...

[Dan Sikorski]

Mike Hebel wrote:
> But I'm kind of curious why 2 of the machines are running PAE kernels and
> the others aren't even though they all show as XP Pro 2002 SP3.
>   

This might offer an explanation:

http://en.wikipedia.org/wiki/Physical_Address_Extension

 From the Windows section:

"Windows XP SP2 and later, by default, on processors with the no-execute 
(NX) <http://en.wikipedia.org/wiki/NX_bit> or execute-disable (XD) 
<http://en.wikipedia.org/wiki/NX_bit> feature, runs in PAE mode in order 
to allow NX. The NX (or XD) bit resides in bit 63 of the page table 
entry and, without PAE, page table entries only have 32 bits; therefore 
PAE mode is required if the NX feature is to be exploited. However, 
desktop versions of Windows (Windows XP, Windows Vista) limit physical 
address space to 4 GB for driver compatibility reasons."


    -Dan Sikorski