Is OSX known for high RAM usage?

The Seventh One · 28 Oct 2013 at 22:29

Hi all,

I'm a newcomer when it comes to Mac as I've only had this MBA a few weeks and I'm really chuffed with it... but tonight I opened resource monitor and I was totally shocked.

I had literally no apps or programs running and 5.5GB of RAM was being used, I've now restarted and still have 2.5GB used which seems a bit high for idle if you ask me. There is nothing that stands out in terms of one particular process eating up a large chunk but there was a ton of small processes.

Is this normal for a Mac or has something gone wrong somewhere, perhaps with the Mavericks upgrade?

Many thanks for any help!

PardonTheWait · 28 Oct 2013 at 23:03

I've heard from a few people that it will happily use more if it's got more. They appear to have changed the way Activity Monitor shows RAM by the looks of things but for example mine's showing 5.4GB as file cache, 3.08 as App Memory. I don't recall there being a file cache section listed before, but I might be going mental. Or possibly it's been renamed.

Either way the file cache could just be 5GB of stuff that it hasn't cleared yet because nothing else needs the space. If you've got it, use it I guess.

Hxc · 28 Oct 2013 at 23:18

If you've got RAM, why not use it? I've never understood this mentality.

Scythe · 29 Oct 2013 at 00:26

Mavericks loads your commonly used programs into RAM and tries to maximise usage, so yes it is expected. It will reallocate as necessary to new tasks as required.

As with most things with OSX, don't worry about it.

MagicBoy · 29 Oct 2013 at 00:41

It's the way OS X works. Stop thinking it's Windows.

Just let OS X get on with managing the memory and enjoy using your Mac.

Audigex · 29 Oct 2013 at 17:25

Windows does this too, it just reports things differently

In the resource monitor you can see 4 "categories" for RAM
1) Free
2) Wired
3) Active
4) Inactive

And an "In Use" category which is the sum of wired, active and inactive.

Free is obviously unused RAM. Wired is critical system etc RAM which cannot be paged - it has to stay in memory.

But Inactive and Active is where things get a bit different. Active is stuff that is in use by a program now or is being held for use soon... this will be paged if there is no Free or Inactive RAM available, but will be held in memory where possible.

Inactive is things that have been used recently and not been fully released. It is held in memory until there is no more free memory, then released/paged to be used as necessary. This will be released/paged before active memory, but is kept "in case" it is needed soon. Usually a program which you have closed recently and no longer need in memory, but available if you need it. Windows generally unloads this immediately and declares it as "free" memory.

So really your free memory is all of your Free and Inactive memory, while even Active memory may not be being fully used - ie background programs. All of the above can be either released or paged if necessary. Only the Wired memory is untouchable.

But as above, unless you're noticing things slowing down, don't worry about it - OSX memory management is excellent, and the philosophy of "keep it in memory until something else needs the space" is a good one.

The Seventh One · 29 Oct 2013 at 19:09

Thanks for the replies all, admittedly I haven't noticed any slowdown. It was more of a curiosity thing as I'm not used to seeing that much utilisation in Windows unless I've got a lot of stuff going on!