[CentOS] Adding RAM

Adam Tauno Williams awilliam at whitemice.org
Sat Dec 6 14:27:12 UTC 2008

> >> 2008/12/5 Matt <lm7812 at gmail.com>:
> >>> I have a server running Centos 4.7 32bit.  Will moving from 4Gig of
> >>> RAM to 8Gig do any good?  Since its 32bit I assume it will only be
> >>> able to address the first 4Gig not?
> >> As long as you are using a SMP kernel you can use up to 64GB of RAM
> >> (though each proccess can only address 4GB of this). So if you can
> >> find any trace of  "SMP" in the uname (grep is your friend) then it
> >> should work fine.
> > PAE, not SMP
> He should be able to replace the kernel via rpm -e and rpm -i
> That said, I doubt he'll actually see a benefit.
> PAE is slow.

It isn't slow;  it does have a performance penalty.  A 32bit box with
8GB serving many clients (as an IMAP server, file server, etc...) will
be faster than a 32bit box with 3GB of RAM.

More information about the CentOS mailing list