Q: Last week, you suggested adding more RAM to your computer may be the best investment you can make in optimizing its performance. But how much RAM is the correct amount? I’m using a Mac computer.
A: The easy – though also true – answer is as much RAM as possible! But for an objective look at the memory usage in your Mac (assuming you are running OS X), use the Activity Monitor application in your Applications>Utilities folder. The RSIZE (or real memory) column in the display indicates how much RAM a program is currently using.
However, note that the RAM usage numbers reported will change based on activity within the program, caching, open files, etc.
At the bottom of the screen, under the “System Memory” tab, is a report on total memory usage, with a pie chart. “Free” memory is unused by the system or an application. “Wired” memory is reserved by the system and drivers. “Active” memory is used by the system or by programs that are running. “Inactive” memory is being used as a disk I/O cache. “Used” is the total amount of memory being used by the system and any programs that are running.