Doesn't PAE break the NX bit?
- Data Execution Protection is more important.
- No Win32 (std) process can allocate more than 2GB RAM anyway
- Yes the other 2GB will be used, as you'll be running 80 or so processes (not processors) 'at once', plus the kernel.
32-bit Windows has smaller pointers, so for most apps (85%+) it's faster and uses less memory.