It's important to remember that when using AWE memory in SQL Server 2000, only the buffer pool pages can be stored in AWE. That means that only plain ol' tabular data can be stored in the memory over 3GB.  All other memory needs, like as sort and hash worktables or the contents of table variables, must be stored in the regular virtual address space (VAS).  And, depending on your boot.ini settings, VAS is never more than either 2 or 3 gigabytes.

That means that there are applications that can be better served by not using AWE.  Why?  Because VAS isn't required to mapping pages to the data stored in AWE.  So in certain memory starved applications, you might want to experiment with what happens with AWE disabled. It's possible that you might do better without AWE enabled!

And if you're ever looking for more information on memory management in SQL Server, check out Slava's very technical blog: http://blogs.msdn.com/slavao/default.aspx.  It's the best!

Enjoy,

-Kevin