Sidebar Sidebar
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

Free RAM becomes Inactive after amount of idle time.

WeegieMac

WeegieMac

Guest
Original poster
Jan 29, 2008
3,274
1
Glasgow, UK
Has anyone come across this, and is it a bug?

My iMac has 4GB of RAM, and right now I have Safari (3 tabs) and iTunes open (doing nothing but syncing apps to my iPhone).

I had 2.99GB of free memory on Activity Monitor, and I went downstairs to prepare dinner and left the Mac running. When I returned some 40 minutes later and checked Activity Monitor again, that 2.99GB of RAM is now showing as Inactive, with 30.8mb of Free Memory available.

Nothing else opened, nothing else running.

Anyone?
 
What is the problem here? You do know that inactive RAM is just as available as free RAM, right?
 
If your not getting any large page-outs in Activity Monitor, then don't worry about it because In-active memory is just as good as Free memory (actualy better because it has data already cached for future use).
See: http://support.apple.com/kb/ht1342

I've got a 4GB MacBook Air with 2.8GB Inactive, 100MB Free that's been running for a few days and I only have 3MB of page-outs.

Also OS X probably uses free RAM as a disk cache (I know Windows does) when copy-pasting/moving files, which is why if your syncing Apps your Free memory is going down.

.​
 
Last edited:
Quad5Ny said:
If your not getting any large page-outs in Activity Monitor, then don't worry about it because In-active memory is just as good as Free memory (actualy better because it has data already cached for future use).
See: http://support.apple.com/kb/ht1342

I've got a 4GB MacBook Air with 2.8GB Inactive, 100MB Free that's been running for a few days and I only have 3MB of page-outs.

Also OS X probably uses free RAM as a disk cache (I know Windows does) when copy-pasting/moving files, which is why if your syncing Apps your Free memory is going down.

.​
Click to expand...

Those numbers are actually near identical to my system, including page outs.

I've never seen such a quick and vast change from free to inactive, and I've been an OS X user since Panther. It was the straight swap of 2.99 free to 2.99 inactive after some idle time that made me wonder.

Thanks for your reply :)
 
Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_3_5 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8L1 Safari/6533.18.5)

I have 8gb and the very same happens to me with the difference that lion does not utilise the inactive ram properly, I am still getting page outs occasionally using only apple apps. It's ridiculous.
 
I'm actually pretty disheartened to come back and notice that my genuine question has been marked down by someone ... what has happened to this site?
 
WeegieMac said:
I'm actually pretty disheartened to come back and notice that my genuine question has been marked down by someone ... what has happened to this site?
Click to expand...

Don't take it personally, people are just passionate about their OS. There have been many threads bashing Lion for 'bugs' that are not actually resulting from the OS. Some people are just frustrated hearing about 'serious Lion issues' that end up being either user error or hardware problems. And let's be fair, your first sentence suggests a bug were none exists.
 
I upgraded my iMac to 12Gb for Lion and I'm seeing the same problem.

I like to run a lot of apps at once, so thought it would be a good idea to bump the memory up. Currently my iMac has been up for 9 days and it's running the App Store, Mail, Safari, iCal, iTunes, 1Password, Twitter, Evernote, Terminal and Activity Monitor. There's been other apps open in this period too such as iPhoto, PSE 9, WoW, Steam and Xcode.

As always with Lion, kernel_task has grown over this time and is now at 890Mb, Safari has been restarted recently so is only at 663Mb but it was a lot higher and I have no idea why Mail is taking 521Mb, that just insane.

Lion definitely has some memory issues.
 

Attachments

  • Screen Shot 2011-08-26 at 07.51.32.png
    Screen Shot 2011-08-26 at 07.51.32.png
    20.2 KB · Views: 107
  • Screen Shot 2011-08-26 at 07.54.45.png
    Screen Shot 2011-08-26 at 07.54.45.png
    34.7 KB · Views: 101
AndyMoore said:
Lion definitely has some memory issues.
Click to expand...

I am seeing the same memory usage patterns with Mac OS X 10.7.x that I saw with Mac OS X 10.6.x.

I restart Firefox every once in a while, just like before I upgraded the OS, because it has always had some type of memory leak or does a lot of undocumented data caching in memory.

I am using Apple Mail instead of Thunderbird now. I don't see a big difference between the two in regards to memory usage. I sure like Apple mail better though.

S-
 
Thanks for the replies folks :)

I know about inactive RAM essentially being free RAM that's good to go when called upon. However I've never seen such a switch, essentially all available free RAM changing to inactive, to the exact number.

I just thought it was a bit odd, as I've never seen that shift of free to inactive in OS X before, and usually only seen inactive RAM appear when a previously open application was quit.

That's all I meant. :)
 
I'm having problems as well. Inactive RAM isn't just as good as free RAM because I can max out my 4GB RAM for minutes and that 1GB part that is inactive just never frees up unless I use an app like iFreeMem.
 
Inactive memory can stay Inactive, well forever. It depends on what the OS feels like doing with it.

But OS X SHOULD free Inactive memory when a application requests it.
 
This is not an isolated incident. I never had this problem with SL or prior, till I upgraded to Lion. I have 8 GB of memory with hardly two or three browser tabs open, and my system will become sluggish after a while. I go to the activity monitor, and guess what? I have absolutely zero free memory, lots of inactive memory and lots of pageouts(weird for a system with 8 GB of ram with not that much of memory use). I need to purge the memory to free my system.
 
That happened to me too. I don't know if its related to the fact that I disabled dynamic pager but it never happened again. I'm using iTunes and Firefox and I still have about 6,3gb of ram free.
I remember having to purge every time the ram filled up or it would start to go haywire.
 
blackburn said:
That happened to me too. I don't know if its related to the fact that I disabled dynamic pager but it never happened again. I'm using iTunes and Firefox and I still have about 6,3gb of ram free.
I remember having to purge every time the ram filled up or it would start to go haywire.
Click to expand...

how do you know if you have the dynamic pager disabled?
 
Free RAM is wasted RAM. Inactive is just the OS antipating future needs and keeping data loaded on stand by. If free RAM is needed, inactive RAM can be immediately returned to the free pool.
For all practical purposes, consider your free pool to the the combine total of free plus inactive.
 
err404 said:
Free RAM is wasted RAM. Inactive is just the OS antipating future needs and keeping data loaded on stand by. If free RAM is needed, inactive RAM can be immediately returned to the free pool.
For all practical purposes, consider your free pool to the the combine total of free plus inactive.
Click to expand...

Well, I find that animations in Lion (going to/from full screen in apps and launching Launchpad) are significantly more sluggish and lacking in frame rate with a load of inactive RAM, compared to when that same allocation is free.

If I had opened a lot of apps, then closed them, then fine ... inactive RAM is explained. But to have a system that had been switched on, had run Safari and iTunes, then been left idle, to swap it's entire free RAM to inactive, seems somewhat "odd".
 
You must log in or register to reply here.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.
Top Bottom
Back