RAM usage keeps increasing?

[Khryz]

Just want to confirm that this is what is supposed to happen. I have a 2.16 GHz Macbook that I upgraded to 4GB of RAM (although only 3GB is used). When it starts up it hovers around 30% RAM usage (iStat Menus) with Dashboard, Mail, iTunes, Firefox, Adium, Address Book and iCal open. As time goes on, it keeps increasing and now iStat Menus tells me it's at 73% (if I show Inactive RAM as Free RAM, without that it's 79%) currently. Right now I apparently have 1.85 GB of Active RAM.

Is the RAM supposed to keep going up and up? I'm not doing anything crazy just listening to iTunes while surfing Firefox while checking my mail.

 

[alphaod]

Yes it normal for RAM usage to go up. When another program requires the allocated RAM the former program will give up some.

 

[iToaster]

OS X keeps recent items stored in the RAM for faster access, so it's really nothing to worry about.