OS-X 10.8.4 Curiosity

I've discovered OS-X 10.8.4 eats unidentifiable memory, or at least it's not obvious from looking the Activity Monitor. What's the curiosity?

When I reboot the Mac Pro and establish the initial state of processes, here's the summary of the memory:

Wired    - 890 MBytes
Active   - 790 MBytes
Inactive - 20 Mbytes

That leaves 1.7 GBytes used and 14.3 GBytes free.

After a week of normal use I return the Mac to the initial state and after the purge command here's the summary of the memory :

Wird      - 1.29 GBytes
Active   - 2.00 GBytes
Inactive - 100 MBytes

That leaves 3.4 GBytes used and 12.6 GBytes free.

I can understand the wired memory increase, but I can't understand the active memory increase of 1.3 GBytes when there's nothing obvious running. I can only suspect Apple changed how it uses previous used applications and reserves active memory for them so they open sooner and faster than if they were in inactive memory.

I notice this because I can close an application and open it later to see it loads and opens sooner and faster. But what Apple doesn't do is provide the user with a tool or command to recover the unused active memory. The purge command only recovers inactive memory.

I know that if the space was necessary for new applications, files, etc. OS-X would recover the memory and use it. But why not give the user a way to recover it now so it doesn't have to page out or swap memory which only adds to the time to load and open.

Anyway, I'm open to ideas but I don't like the way this works especially since some applications are notoriously memory hogs and keeping them in unused active memory after closing isn't efficient except if you use the application again. Otherwise it's a waste of memory.