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Inactive RAM taking over!

Mrguidogenio

Mrguidogenio

macrumors regular
Original poster
Jun 4, 2011
222
1
Argentina
Since yesterday, my MacBook Pro 13" 2011 with 4 GB of RAM started doing a strange thing: A lot of times my Inactive RAM will go from 200 MB to 1.3 GB, making my free RAM less than 100 MB and slowing down the machine. I have to fire up Terminal and type "purge" in order to restore my Free RAM to almost 2 GB again and the system to normal state.

I have inspected my Activity Monitor and neither process appears to use lot of CPU nor RAM. I don't understand why the Inactive RAM is doing this.

Anyone else experiencing this too since the Lion upgrade?
 
Last edited:
Mrguidogenio said:
Since yesterday, my MacBook Pro 13" 2011 with 4 GB of RAM started doing a strange thing: A lot of times my Inactive RAM will go from 200 MB to 1.3 GB, making my free RAM less than 100 MB and slowing down the machine. I have to fire up Terminal and type "purge" in order to restore my Free RAM to almost 2 GB again and the system to normal state.

I have inspected my Activity Monitor and neither process appears to use lot of CPU nor RAM. I don't understand why the Inactive RAM is doing this.

Anyone else experiencing this too since the Lion upgrade?
Click to expand...

Inactive RAM is just stale RAM... it's not Wired or Active...
 
More precisely Inactive memory is old active memory that's no longer in use. It's kept cached incase a application needs it again, therefore reducing launch/load times.

The system and/or application can request to free inactive memory or move it back to the active pool at any time to make use of it.

http://support.apple.com/kb/ht1342
 
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People, I know what's Inactive RAM. The fact is that it gets suddenly form 200 MB to 1.5 GB, SLOWS down my Mac and freezes everything. It won't get released, so To take control I have to use the "purge" command.
This is not normal. It freezes my Mac.
 
Mrguidogenio said:
People, I know what's Inactive RAM. The fact is that it gets suddenly form 200 MB to 1.5 GB, SLOWS down my Mac and freezes everything. It won't get released, so To take control I have to use the "purge" command.
This is not normal. It freezes my Mac.
Click to expand...

Inactive RAM is freed...

From http://support.apple.com/kb/ht1342:
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.
Click to expand...
 
Mrguidogenio said:
Why nobody understands? The Inactive RAM FREEZES my Mac and it won't unfreeze unless I manually run "purge". Why nobody understands what I mean?

This is not normal. The Mac becomes slow as hell.
Click to expand...

I think people are being purposely obtuse.

Lion is a mess. Many of us are experiencing this first-hand, others don't want to know.
 
HellDiverUK said:
No, it doesn't. Something freezes your Mac, but it's not inactive RAM.
Click to expand...

Then why before it freezes my Inactive RAM is 200 MB, after freezing I can see in Activity Monitor that it's 1.5 GB, after I Purge the Mac it restores to normal and the Inactive becomes 200 MB again?
Nor process is taking the whole CPU nor the whole Active RAM.
 
Mrguidogenio said:
Why nobody understands? The Inactive RAM FREEZES my Mac and it won't unfreeze unless I manually run "purge". Why nobody understands what I mean?

This is not normal. The Mac becomes slow as hell.
Click to expand...

You don't understand how RAM works, if your Inactive RAM jumps, that means that some program just exited that used the difference. Something else is causing your Mac to freeze.
 
Nuckinfuts said:
You don't understand how RAM works, if your Inactive RAM jumps, that means that some program just exited that used the difference. Something else is causing your Mac to freeze.
Click to expand...

yes, something is slamming your ram, freezing it, then crashing...therefore sending all your ram into inactive.
 
tom5304 said:
I think people are being purposely obtuse.
Click to expand...

No, you're both thick as hell. Restating the posted support doc: inactive memory will be overwritten as needed, with no performance penalty relative to free memory. Free memory is wasted memory; a "smart" OS will fill it with prefetched data (à la Windows Vista/7).

If you're having performance problems, the root cause lies elsewhere.
 
I've noticed that when I have less than 200MB or so of free ram that my computer is slow as hell. Even though there is plenty of inactive ram
 
I'm afraid I don't have a solution, but I can at least echo Mrguidogenio's sentiment. I've seen Inactive Memory eat up Free like crazy, as much as 1.5GBs. It gets to the point that it force the system to page out which does indeed slow down performance. I picked up a little utility from the Mac App store called iCleanMemory that will reclaim some RAM, but this is a band aid on a larger problem. I'm hoping a point update to Lion will patch a lot of these annoyances. Here's a screen shot of what my activity monitor often looks like: http://cl.ly/3U1P360j2E3D353C272Q
 
exzador said:
I'm afraid I don't have a solution, but I can at least echo Mrguidogenio's sentiment. I've seen Inactive Memory eat up Free like crazy, as much as 1.5GBs. It gets to the point that it force the system to page out which does indeed slow down performance. I picked up a little utility from the Mac App store called iCleanMemory that will reclaim some RAM, but this is a band aid on a larger problem. I'm hoping a point update to Lion will patch a lot of these annoyances. Here's a screen shot of what my activity monitor often looks like: http://cl.ly/3U1P360j2E3D353C272Q
Click to expand...

Inactive RAM cannot cause Page outs, period. Understand RAM before you start diagnosing it.
 
Nuckinfuts said:
Inactive RAM cannot cause Page outs, period. Understand RAM before you start diagnosing it.
Click to expand...

I think you might be misreading what he wrote, or I am very confused also

eg

Free Ram = 50 MB
Inactive RAM = 500 MB

If I launch another app that requires large amounts of RAM, I understand that this should use the Inactive Ram as I dont have enough Free RAM available

What seems to happen is that instead of using the Inactive RAM, this new app starts paging out because there is not enough Free RAM

So in a way Inactive RAM is causing page outs as it is not releasing this RAM for other Apps

just tested this

had 80 MB free
600 MB inactive

launched Aperture
free went down to 10MB free
inactive stayed at 600
page outs went to 500 MB

closed Aperture
free went to 500MB
inactive went to 100MB
 
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paulsalter said:
I think you might be misreading what he wrote, or I am very confused also

eg

Free Ram = 50 MB
Inactive RAM = 500 MB

If I launch another app that requires large amounts of RAM, I understand that this should use the Inactive Ram as I dont have enough Free RAM available

What seems to happen is that instead of using the Inactive RAM, this new app starts paging out because there is not enough Free RAM

So in a way Inactive RAM is causing page outs as it is not releasing this RAM for other Apps

just tested this

had 80 MB free
600 MB inactive

launched Aperture
free went down to 10MB free
inactive stayed at 600
page outs went to 500 MB

closed Aperture
free went to 500MB
inactive went to 100MB
Click to expand...

I get the same thing. Just put another 4 GB in my 2010 mac mini and I'm getting more page outs in Lion than I ever had in Snow Leopard
 
I think inactive memory is memory that can by released by the application if other applications need it, but it can take time for the application to handle it. which causes page outs. 4GB generally causes lot of page outs, even for basic stuff.
 
ztrafe said:
I think inactive memory is memory that can by released by the application if other applications need it, but it can take time for the application to handle it. which causes page outs.
Click to expand...
More importantly, just because memory is marked as inactive doesn't mean it can always be freed. Inactive memory could be due to (1) app that has been terminated (in which case OS can reclaim it) or (2) app just hasn't been used in awhile. For the later case, Lion now has "sudden termination" feature. That is, if an app has "sudden termination" support, Lion can reclaim its inactive memory for other apps.
 
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