I am considering using Apache 32-bit for a [Moodle](http://www.moodle.com/) installation on a Windows 2008 R2 64-bit/16GB server. Since the available memory affects the number of concurrent of users that can be served, I was wondering how the 2GB memory limit on 32-bit Windows processes affects Apache+PHP.

Is it a collective limit for the whole server, or is it applied separately for each Apache child process/thread?

If it is separate, how many of those children are launched on Windows? One per request? One per processor core? Something in the middle? Is this somehow configurable?