Lots of information on websites state that Mac is really good for memory management and you shouldn’t worry too much about it as Mac will handle it for you nicely. However, I have found it very untrue.
My MacBook Pro has 8GB of memory, but it always climbs up to use all my momeries and slows down everything.
You can see that I only had 33MB of memory left to use. There were more than 2GB of inactive memories that can be re-claim but Mac had refused to do so. My system becomes un-responsive proved it. Most of cases I have to quit certain memory hungry applications and restart them to re-claim some memory back, like FF4 who has been famous from its memory management.
Just in case you might wonder what those memories mean:
Free memory is available to be used right now
Wired memory is basically system memory for the kernel and other stuff
Active memory is memory being used right now
Inactive memory stores info from recently quit applications. The idea with inactive memory is that if you quit and app and start it up again it’s going to launch nice and quick because the info is still in RAM.
There is a “purge” command in Mac if you have installed developer tools which will allow you to force Mac to re-claim memories in the In-active state. However, your computer will become un-responsive during the operation, which normally takes from 30 seconds to up to more than 1 minutes.
This is a command that I don’t think you should use often as it freezes up your system for a while, I will only use it when it is absolutely necessary.
There is not much you can do about it unless Apple solves this problem, but I doubt it in the short term.