Re: RHEL4 x86 kernel with more than 4 GB of RAM

[Micah Yoder <myoder hcjb org ec>]

> > Does that mean that all kernel-smp packages have the PAE performance
> > hit, even if you have less than 4GB of RAM?
>
> yes it means exactly that.
>
> (but it's only 6% on database workloads)
>
> > I am asking this since I don't need 6GB of RAM for now and, if I can
> > avoid the performance hit by decreasing the memory to 4GB, I'll just
> > take out a 2GB module from the server.
>
> that won't fly ;( if you do that you get all of the pain of PAE but none
> of the gain of the extra ram...

Whoa, this is surprising news to me.

We have an RHEL mail server, which sometimes performs more poorly than we'd 
like.  It is a Poweredge 750 with a hyperthreading CPU and one gig of RAM.  
We use the smp kernel.

Would it make any sense to rebuild the kernel with PAE off?