How to Monitor memory use in Mac OS X with Activity Monitor
You can use Activity Monitor to see how your Mac is using memory. But what do free, active, inactive and wired mean? How about page ins and page outs? Plus, learn to use them to figure out if you need more memory. It's easy! So easy, in fact, that this home-computing how-to from MacMost can present a full overview of the process in about four minutes. For more information, including detailed, step-by-step instructions, and to get started monitoring your own RAM use, watch this Apple lover's guide.