On Tuesday 19 June 2012, "Hugh E Cruickshank" hugh@forsoft.com wrote:
If that is the case then both CentOS 5 and 6 are not viable for us. I will have to go for RHEL5 (or possibly 6) which does support the memory in 32-bit mode.
The limit's the same with RHEL 5 and 6. CentOS is "bug-for-bug compatible" with RHEL.
The reason for the restriction to 32-bit is because of other software that we must run that does not work correctly on a 64-bit OS.
Your 32-bit applications will be restricted to 4 Gb of memory each anyway. If you must use x86, memory over 16 Gb is pretty much wasted, unless you install x86_64 and virtualize x86 as necessary.