Load average & Memory used

[unknownsheep]

Hello, i have two questions about load average and memory used which is displayed when running the top command.
Im running Debian etch and these screenshots are taken through putty.

Image: http://c.imagehost.org/0374/screens.png

Picture 1:
How could I possibly have a load average of 4.97? Im using an Intel dualcore.

Picture 2:
Why does it say that im using a whopping 2024532 KB memory while the processes in the list (ordered by memory usage) only uses a total of 612634 KB?

TOTAL = 2076724 KB (2030 MB) = 100 %
USED = 2024532 KB (1980 MB) = 97.4 %
LIST = 612634 KB (598 MB) = 29.5 %

612634 KB != 2024532 KB

[coopstah13]

1. your uptime is 32 days, and probably a high amount of that time the computer was idle

2. the rest of the memory is being used by buffers and/or cache

free -m

[unknownsheep]

Thanks for your reply!

1. A bit confusing but okey..

2. Ah okey, free -m returns this:

         total       used       free     shared    buffers     cached
Mem:     2028        1976       51       0         20          1432

So what exactly does cached means? and should I do anything about it?

EDIT:

I googled it and found this page: FAQ Linux Memory Management - Gentoo Linux Wiki

So basically the cache is for storing data for quick access and could be used by applications if needed and there is no reason to worry? right?

[coopstah13]

linux memory management is different from windows, linux will store things in cache that have been accessed from disk in order to help increase performance of subsequent uses of that data, almost all your memory being used for cache is normal I have a 32 gb system at work and 16 gb is cache