800MB RAM Usage with nothing running?

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Level 2

230 points

800MB RAM Usage with nothing running?

I am pretty confused, my MacBook seems to be using a lot of memory with nothing significant running. I've cleaned all caches, and ran all the maintenance scripts, but from shutdown to restart, with nothing running (not even dashboard), it shows over 800MB of RAM in use. 250MB of that is wired, 750MB is active. I've checked my login items, and there's nothing that would cause such a large usage of RAM running. Even when I start the Activity Monitor, it doesn't even list anything using so much RAM. There's like 20-40MB RAM for the kernel task, window server and default stuff like that.

Basically there seems to be a large amount of RAM used that I have no idea what is using it. Any clue at all what could be causing this?

MacBook 2.4GHz C2D - 2GB RAM - 160GB HDD, Mac OS X (10.5), Airport Extreme - Superdrive

Posted on Nov 15, 2008 2:10 PM

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Answer 1

baltwo

Level 9

62,386 points

Nov 15, 2008 2:20 PM in response to Balazs Hollos

Activity Monitor in /Applications/Utilities/ will show you what's running if you select All Processes.

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Answer 2

Kappy

Level 10

362,007 points

Nov 15, 2008 2:21 PM in response to Balazs Hollos

So you have 800 MBs of RAM in use. Why is that a problem? See the following:

About OS X Memory Management and Usage

Reading system memory usage in Activity Monitor
Memory Management in Mac OS X
Performance Guidelines- Memory Management in Mac OS X
A detailed look at memory usage in OS X

Understanding top output in the Terminal

The amount of available RAM for applications is the sum of Free RAM and Inactive RAM. This will change as applications are opened and closed or change from active to inactive status. The Swap figure represents an estimate of the total amount of swap space required for VM if used, but does not necessarily indicate the actual size of the existing swap file. If you are really in need of more RAM that would be indicated by how frequently the system uses VM. If you open the Terminal and run the top command at the prompt you will find information reported on Pageins () and Pageouts (). Pageouts () is the important figure. If the value in the parentheses is 0 (zero) then OS X is not making instantaneous use of VM which means you have adequate physical RAM for the system with the applications you have loaded. If the figure in parentheses is running positive and your hard drive is constantly being used (thrashing) then you need more physical RAM.

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Answer 3

nerowolfe

Level 6

13,090 points

Nov 15, 2008 2:26 PM in response to Balazs Hollos

Balazs Hollos wrote:
I am pretty confused, my MacBook seems to be using a lot of memory with nothing significant running.

When you say nothing significant, are you not forgetting the operating system?
Create a new, non-admin user and run AM. Add up the usage in the real, virtual and private memory columns and see if they check with the totals.

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Answer 4

BobHarris

Level 9

56,939 points

Nov 15, 2008 3:59 PM in response to Kappy

If you want to see your pageout activity over time, then from an Applications -> Utilities -> Terminal session, run the following command:


sar -g 60 100

which will tell you your pageout activity every minute for 100 minutes.

Sustained high numbers is an indication that you either need to stop trying to do everything at Once, or you could use more memory.

But mostly zeros, with some minor bursts of pageouts from time to time is just noise and should be ignored, unless those bursts occur just when you notice that the system is annoyingly slow.

And of course if money is no object, then buy more memory. The memory vendors will love you 🙂

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