First of all i'd like to ask politely for all of those who feel the need to explain it to me how perfect apple's memory management is to ignore this thread.

A little background:

The theory goes that if you have lots of inactive memory - it's can be freed for applications that need it. It's like free memory according to apple and their blind followers. And i like the idea of it, but... in practice: when free memory hits low numbers and inactive hits high numbers - osx (at least snow leopard) slows down ... So even if the inactive memory is being freed - it is done very very slow and that's not acceptable.

But for some reason the problem has just gotten worse for me: i've just noticed that inactive memory keeps piling up faster than ever. I've done a couple of purges just to confirm my theory and ... the number gets high again very fast ...

So until apple fixes whatever is wrong with their memory management - i'd at least like to know which apps are producing the inactive memory.

Is there a way to somehow monitor processes and see how much memory they allocate and free during their lifetime?

Thanks for your thoughts

  • This isn't quite clear--do you mean something more specialized than Activity Monitor?
    – Zo219
    Commented Jan 17, 2013 at 7:13
  • Yes. Maybe a shell command or smth like that. Or some other in-depth process monitor able to track memory allocations.
    – Marius
    Commented Jan 17, 2013 at 13:18
  • Marius, me too. I installed 'Free Memory' to clear that inactive memory for me automatically, it needs to do it several times a day. Right now I have 900MB free and 3GB inactive. Its a super irritating problem and I would love to know what I can do to fix it.
    – Christian
    Commented Feb 1, 2013 at 23:57
  • 1
    @Christian: if you have enough ram you can disable virtual memory alltogether. Mac's memory management is amazing in theory, but in practice i've never seen anything more terrible. There's also some sort of replacement for mac's default pager to overrade swapping settings. So, there's two things you could try if you're brave enough :)
    – Marius
    Commented Feb 5, 2013 at 14:36
  • Thanks @Marius - have you read this? superuser.com/questions/317215/…
    – Christian
    Commented Feb 6, 2013 at 4:49

1 Answer 1


I have had some success using the terminal command top. Much the same results as Activity Monitor, but I can slow down the update speed, and sort on any field.

In my experience, the problem is usually with individual programs that fail to free memory. You will see the memory for that process creep up. See 'man top' for details about the various fields that top reports. Firefox is notorious for this, and with 60 or so tabs requires a restart every few days

If you want to dig deeper, vmmap can give you the status of pages owned by a particular process.

Be warned: sometimes slowdowns are CPU related. Sometimes disk i/o related, althoth the latter is less common with current memory prices.

  • Thanks for your answer. Found out it was something as simple as VLC... If that can make my ram go crazy ... imagine what all the development environments and photoshops does ...
    – Marius
    Commented Mar 20, 2013 at 12:51
  • It's likely a glitch, so Xcode and final cut run just fun on most machines :P
    – Alexander
    Commented Mar 21, 2013 at 21:28

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