A) This switch has nothing to do with "physical memory" - so you have
a machine with 4GB of memory - so what - I do too!
B) This switch is used to change that amount of addressable "Virtual
Memory" an application has available (See Below).
C) Only server based application are written to make use of the 3GB
Virtual Memory Addressable space, so it really has not use on NT WS
4.0, 2k Pro or XP - except is shortchanges the OS of 1GB of Virtual
Memory Addressable space, in essence making the executive swap more,
decreasing the performance of your PC.
This switch made its debut in NT 4.0 Service Pack 3 and is supported
on all later releases of NT. It will cause the split between the user
and system portions of NT's virtual address map to move from 2GB user,
2GB system to 3GB user, 1GB system. Giving virtual memory intensive
applications like database servers a larger address space can improve
their performance. Note, however that for an application to take
advantage of this feature two additional conditions must hold: The
system must be part of the NT Enterprise suite (SP3 is not) and the
application must be flagged as a 3GB-aware application. See Microsoft
KB Article Q171793 for additional information.
