I ran an interesting test just to see how much resource OS-X 10.8.2 eats over times. Eating meaning using resources it's using above what it used shortly after rebooting (using the purge command to clear unused active and inactive resources).
I ran the test right after rebooting with only three apps running, Activity Monitor, Console and Terminal windows. Then I ran it again after bringing up all my basic apps, iTunes, Adobe Bridge CS6, Safari and Mail along with 22 menu bar apps.
Right after rebooting, the Mac (Pro dual 2 x 2.4 GHz with 8 cards of 2 GB memory ECC for 16 GB of memory) uses the following:
Wired - 900 MB
Active - 914 MB
Inactive - 24.6 MB
Used - 1.80 GB
With all the apps opened but not used yet:
Wired - 1.02 GB
Active - 2.24 GB
Inactive - 53.2 MB
Used - 3.26 GB
After a week of running with just the same apps opened:
Wired - 1.32 GB
Active - 3.14 GB
Inactive - 110 Mb
Used - 4.46 GB
In all of these cases, the numbers were taken after the purge command. There was a gain of 900 MB for the active memory and 57 MB of inactive memory over the week. The wired memory seems to stablize quickly in a day or so with the kernal process taking most of the new memory.
Much of the additional active memory was taken by iTunes and especially Adobe Bridge, which is why I suggested in another post to close all Adobe apps you don't plan to use for awhile, they eat memory just sitting there open and hidden, especially the adobe crash daemon, often the latter taken most memory than the app itself.
Anyway, it's just an observation. About once a week or so close all the apps and reboot, especially after doing a lot of work with a few apps or having had a lot of apps opened for awhile. This isn't critical or really even important, but just to reset all the resources.
A note about rebooting. Close all apps before rebooting. It saves on the reboot. I only keep one app open when I reboot to open when I reboot, the Terminal window. This is because there is a bug which writes a lot of messages to the Console which I have to quickly stop after rebooting.
There's a bug somewhere in the com.apple.launchd.peruser file:
which won't stop writing messages about throttling. I've posted it on the Apple Mountain Lion forum but no one has replied with any word, let alone a solution. It's a known bug too.
That's the observation. And yes, I love my Mac Pro.