lammert - 4:39 pm on Dec 5, 2010 (gmt 0)
It is a logical choice of Brett to go for the 32 bit version vs. 64 bit. The limit for Centos 5 is 3GB per process (16GB for the whole system), which is for a web application like this forum more than adequate. The average Apache process running on the server will use in the order of 10MB. The main problem with a 64 bit operating system is that all data is aligned to boundaries of 8 bytes, in general causing 64 bit applications to use about 30% more memory than the same application compiled for a 32 bit OS. And 30% more memory per process counts.