[How to] Clear and Free Up Inactive Memory/RAM in Mac OS X

I absolutely love Mac OS X! And there’s just this 1 thing I really hate about OS X which is the way it manages memory.

Mac OS X has this concept called Inactive Memory wherein the OS stores all frequently used applications on RAM for faster access and less Disk I/O’s. I’ve read numerious articles explaining how this is actually a good feature but I’m not sold on that.

This “Inactive Memory” is supposed to get freed up when you are low on “Free Memory”; however that almost never seems to happen for me and a lot of users out there. The Inactive Memory never seems to get free even when “Free Memory” is around 10Mb and other apps are in dire need of memory!

Take this example, I’ve 8 Gb RAM on my Core i5 iMac. And I use Parallels quite often to run Windows 7 side by side. I’m almost always left with just about 20-30Mb of Free RAM. After that I open up a couple of high resource apps like iPhoto or Photoshop and the Free Memory never increases, causing the apps to take as long as a minute each to load!


There’s an easy solution to this. Simply follow the 2 Steps below:

1. Open Terminal

2. Type in “purge” and press Enter.

You system will sort of freeze for upto 10-20 secs. But after that it will work very smoothly and you’ll have plenty of Free Memory left to open up tons of Apps!

This will especially be useful if, like me, you too tend to fire up Parallels (or any other such Memory hungy App) quite often and find yourself very low on Free RAM.