Darren New <dne### [at] sanrrcom> wrote:
> But the question of "how do you know the memory is 'consumed'?" would 
> likely provide clues towards answering the question of who is using it.

  That's indeed quite relevant.

  The amount of available "free memory" is quite an irrelevant number in
any modern OS (and most of the older ones too). Even Windows. That number
doesn't really say anything. IMO it could and should be removed from the
basic user interface because it only causes confusion and serves no useful
purpose. Even some very experienced users get confused by that number.
Usually many people get worried if the amount of free memory is very low,
even though there's often absolutely nothing to it.

  Sure, the number is telling the amount of memory currently not used by
anything. However, knowing the amount of memory not used currently by
anything is basically useless information because it tells you nothing
about the state of the system. It does *not* tell how much memory will
be available for a program you will be next starting. It does *not* tell
you that the system is running out of memory and that something is wrong
because of that.

  Most OSes will use available free memory for internal things. This is
usually pretty "light" form of usage of memory in that immediately when
a new process requests more memory than is currently unused, that memory
used by the OS for its own things will be immediately freed for the process
to use.
  It may very well happen that the OS reports that there's only 1MB of free
memory in a 1GB system, yet when you start a program requiring half of a
gigabyte of memory, it runs smoothly without even the slightest bit of
swapping or anything. The OS simply stopped using part of that memory and
freed it for the process to use.

  That's why the "memory free" number doesn't really say anything.

-- 
                                                          - Warp

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