interpreting "top" output (computing n% cpu usage in actual megahertz)

[Mark Jayson Alvarez]

Hi,


My goal is to find out how much CPU a program consumes  when I execute it.
In the manual, it says I  can toggle from "raw cpu" mode to "weighted cpu".
However, I can't still understand the difference between the two and how it
has something to
do with my goal. Suppose my computer has a 1.6Ghz pentium 4 processor.
I want to know how much is already in use or what percent. I also want to
know how much it has increased
when I run a particular program so that I can decide if this I can install
this program without affecting other
existing critical programs. The same goes with memory usage.. "Free doesn't
mean that that are all my
memory left that is useable right?
The "Description of Memory" section just says:
Active: number of pages active
Inactive: number of pages inactive

and so on and so forth without telling what the heck does it mean when a
page is inactive and just what does pages
means..

Buf, Free, Wired, Cache... don't know what are these either.. Perhaps I
should consult wiki or google for this.

That's all for now.
Thanks.