Windows 7: Memory Mapping

While going through the BIOS settings on one of my MBs, I found that both hardware and software memory mapping options are enabled. I found this Asus FAQ, which partially explains the settings, but it doesn't say exactly what hardware requirement must be met to use the hardware mapping. Can someone fill me in on this?

http://support.asus.com/faq/asus-faq...Language=en-us

EDIT: Reading closer, I saw where this appears to only apply when one has more than 4GBs if memory. Is this the size of the physical RAM installed, or does it include virtual memory also?



Neither of my machines have in excess of 4GBs, so this may not apply to me anyway. Actually, I was looking for a way to enable "Memory Hole" on my secondary rig, as I have done on my primary rig, to have all of the memory shown as usable, but the secondary rig doesn't seem to have this setting available, even with the newest BIOS installed.

Bump.