On Wed, Nov 17, 2010 at 4:15 PM, Pasi Kärkkäinen <pasik at iki.fi> wrote: > On Tue, Nov 16, 2010 at 04:14:01PM -0600, Barry Brimer wrote: >> Quoting James Bensley <jwbensley at gmail.com>: >> >> > Eh? How can you have 16GBs on a 32bit kernel? >> >> You can have up to 64GB using PAE >> <https://secure.wikimedia.org/wikipedia/en/wiki/Physical_Address_Extension>. >> > > Yeah, but in reality you can't run 64GB 32bit PAE kernel. > All the lowmem would be used for page structs, and the system wouldn't be usable. > > 16GB PAE 32bit system still has some lowmem available.. I think CentOS 4 had a PAE kernel called hugemem that had a 2048/2048 address space that allowed for up to 64GB. That was done away with in 5 I believe in favor of going 64-bit if you have more then 16GB, even if you plan on using 32-bit apps. -Ross