I bought my MacBook Pro about 1.5 years ago (with 4 GB RAM) but these days I think it uses an extraordinary amount of memory; when I open Firefox & Adium & Thunderbird & iTunes & last.fm it uses 3.84 of my 4GB RAM. I must say I installed several 3rd-party software packages on my laptop (maybe on start up they run some process of itself) is there any tool that exists to help me tune my laptop and find what processes run functionless in background, or is there any guideline to help me fix this problem?

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    Firefox is a memory hog. you have to close and re-open frequently. BTW, you have 1.71 GB is in 'inactive' state. That means, it's still available for usage.
    – garikapati
    Jan 11, 2011 at 18:28
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    Also, can you please post the entire Activity Monitor screen shot, sorted by Real Memory? so that we can tell which program using more RAM
    – garikapati
    Jan 11, 2011 at 18:33
  • @garik I know firefox use memory a alot, but with these open software before I use around 2GB of memory, and also fire fox just use 220MB real memeory and 150MB VM in this screen shot :(
    – Am1rr3zA
    Jan 11, 2011 at 18:35
  • Is this a screen shot of AM on a fresh reboot? Jan 11, 2011 at 18:49
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    @Am1 when you get a chance, please post the full screenshot of Monitor.. so that people can check it and offer a soltion.
    – garikapati
    Jan 12, 2011 at 18:31

2 Answers 2


It's probably just been a while since you restarted your computer. When you close a program, the memory it was using doesn't go back to "Free", it gets marked "Inactive". It's still available for use by other programs, though:

Inactive memory

This information in memory is not actively being used, but was recently used.

For example, if you've been using Mail and then quit it, the RAM that Mail was using is marked as Inactive memory. This Inactive memory is available for use by another application, just like Free memory. However, if you open Mail before its Inactive memory is used by a different application, Mail will open quicker because its Inactive memory is converted to Active memory, instead of loading Mail from the slower hard disk.

  • kyle I know this one too but I think I use RAM more than usual I want a solution to tell me what process run on my system(and tell each process blongs to what application) and how much RAM they exactly use.
    – Am1rr3zA
    Jan 11, 2011 at 19:42
  • This is incorrect AFAIK. Inactive pages are pages that a process has allocated but either not used (you do a malloc of a chunk of 32 MB but only use 2 MB, the other 30 MB pages are marked inactive) or the process has not used recently (e.g. the process is asleep or it is a malloc it once allocated then "forgot" about and does not use anymore). The OS marks it as "inactive" so when under memory pressure and the kernel must decide which page to page out, there is a bigger probability that inactive memory pages get into the swap than active pages!
    – Huygens
    Mar 7, 2013 at 22:05
  • ... (follow up, not enough space) then OS X might keep a process once "closed" so it start-up faster if you reopen it. This seems also to be counted in the inactive memory pages. I am not sure how OS X makes the difference between those 2, but one kind would be paged out while the other would be freed. I think one should better trust the output of vm_stat than "Activity Monitor" for what regards inactive pages.
    – Huygens
    Mar 7, 2013 at 22:10

There are probably tools that make it easier to suss things out than using Activity Viewer, but in the end, you just have to be careful what you install. Depending on the applications you install, there may very well be frameworks, daemons, and the like that can run unnecessarily. last.fm is a music streaming application and that is a known resource hog. McAfee AnitVirus is another; I had McAfee slow my machine to a crawl trying to scan my iDisk. The best example I can offer is I got rid of all Adobe applications and related files including Flash off of my home Macs and I found things to be snappier all around (and if I do need Flash for something, which is fast becoming a rare event, I just crack open Google Chrome). I'd say it's simply time for some housecleaning.

  • I uninstall most of my Adobe application too last weak :) but I think I problem somewhere else.
    – Am1rr3zA
    Jan 11, 2011 at 18:38
  • Ouch. Do you have any directory scanning applications running, like McAfee? I think you are in for some trial and error here. To the comments to the questions, browsers in general take up a lot of RAM as well, and they more or less maintain a connection. Anything internet-related is going to take up RAM as well. Jan 11, 2011 at 18:52

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