Memory usage

Can someone explain to me how the OpenSuse 11.2 software uses memory?

Here is why I ask. I have a system with 1 GB RAM. I’m running KDE 4.

I created a tab to look that the Physical Memory in the System Monitor program, which I assume appears to look at the same stats that “top” looks at. In that Physical Memory tab I have 3 tables: Used Memory, Free Memory, and Application Memory.

The Used Memory table shows that the system is using .94 of .98 GiBytes.

The Free Memory table shows that the system has .5 GiBytes of RAM free.

However the Application Memory shows that only 339 M-Bytes of RAM is being used.

Note that “top” shows the same info.

So where is the other .6 GiBytes of RAM that the Used Memory table shows as being used?

If I look at the process table which is supposed to encompass all of the processes running, including the ones for the OS, then it appears to add up to the 339 M-Bytes being used in the Application Memory table.

Is the rest of the memory being held in reserve by the OS to be used as needed?

If so, then why when another application is opened the Free Memory goes down instead of staying constant?

I also noticed this memory “black hole” when I was running 11.0 on a system with 4 GB of RAM. The OS appeared to “take up” a large chunk of memory that was NOT being used by any applications and making it “disappear” - meaning that the applications were using about 1.3 GiBytes of RAM and Free Memory was showing only .7 GiBytes instead of the over 2 GB of RAM that should be free.

I want to be able to run multiple applications, but I cannot be sure that the system resources will allow it since I cannot be sure if there are enough resources.

Which leads me back to my first question on how the OS is using memory.

Any insight will be appreciated.

ronw2 wrote:
> Any insight will be appreciated.


the system you are probably used to doesn’t touch memory unless it is
needed…Linux has a better way: memory which is not used is wasted…

so, if (say) a program loads something (like say a photo) and then you
click to look at another photo, in that other system it would
immediately unload the first photo as it loaded the second…not so in
linux…it hangs on to the first photo just_in_case you ask for it
again soon…and, it will hang on to it until that bit of memory is
required by a new request…

want more? it has been covered hundreds of times in these fora, and
thousands on the web, try here:

DenverD (Linux Counter 282315)
posted via NNTP w/TBird | KDE 3.5.7 | openSUSE 10.3 SMP i686
AMD Athlon 1 GB RAM | GeForce FX 5500 | ASRock K8Upgrade-760GX |
CMedia 9761 AC’97 Audio

That makes sense.