Clearing inactive RAM

Is there anyway to clear inactive RAM without restarting my machine?

You could use:

iFreeMem ($8)
Activata

But you don't need it. OS X is very smart in its use of RAM. It will use as much free RAM as possible to cache things for better performance. And when more free RAM is needed it will flush things.

Two free methods, neither requires any 3rd party software.

ON SNOW LEOPARD:

Open /Applications/Utilities/Terminal

Type

And hit enter. Voila, your RAM is freed up. Stuff will go slower for the next minute or so while your apps cache the stuff that was cached before you purged the inactive RAM, mind you.

ON ANYTHING ELSE:

Open Terminal as stated before. This time the command is:


Why does this work when the du command doesn't actually do anything substantive and all I'm really having you do is display disk usage statistics? Because this forces the hard drive to do a crapton of rapid reads, which in turn causes a lot of pages in memory to get swapped and then freed by the memory management scheme in OS X. Or you could just chalk it up to magic if you prefer.

All this said, if you aren't noticing slowdown in your computer's performance as a direct result of inactive RAM that is not freeing up (due to a badly written program), you shouldn't bother doing either of these. Your computer's programs using as much RAM for cache as possible is a good thing. It makes them snappier. DO NOT USE THESE METHODS JUST BECAUSE THE COLOR BLUE IRKS YOU WHEN YOU LOOK AT ACTIVITY MONITOR. MORE BLUE IS NORMALLY A GOOD THING.