What's eating my RAM?

[portia]

I've installed slackware64-current. The laptop I'm on has been on for the last 4-5 days (with firefox/thunderbird/ktorrent/konsole/xchat on). I checked the RAM usage out of curiosity and I got the following:

             total       used       free     shared    buffers     cached
Mem:          3010       2835        174          0        121       1490
-/+ buffers/cache:       1224       1786
Swap:         2000        130       1870

However, the command 'top' shows that in total there is around 10% of RAM in use at the moment. It would give approximately 300MB, not 2.8GB.
How does it work?

thanks

[jayd512]

Actually memory is not used by application, but it is used for disk caching. If memory is not fully utilized by kernel than it is wasted, but by keeping data in cache when an application needs data again it can be provided faster. If you want to see the memory from the perspective of the application you should look at +- buffers/cache line, the free column of this line shows you the memory that can be used for applications.

[portia]

Ok, thanks it makes more sense now.