Compiz

[David Fox]

On Thu, Dec 4, 2008 at 8:09 AM, Chaman Singh Verma <csv610 at gmail.com> wrote:
> Yes, 310MB, this is what "top" command shows. Not sure, if the "Top" reports
> wrong number.

Mine is 293m virtual, 28 meg real. Not very much. The 293 (or 310 megs
you see) is the maximum request size for the process, not the amount
that the application or process is actually using.

If you are running the latest kubuntu desktop, it uses KDE4, and KDE4
has some rendering capabilities built in, and you might try using
those in place of compiz.

Over here, compiz is not using any cpu either - only if you use the
swticher or other components does it kick in.

And usually the VIRT that top/ps report is inflated, more so for 64
bit processes than 32 bit ones as I recall from running 32 bit systems
(have been using amd64 since May). For instance, top tells me that
firefox wants over a gig of RAM right now per the VIRT size. The
Resident size is much more realistic, unless of course, some pages
have been swapped out.

A better explanation is probably located here.

 http://www.linuxforums.org/misc/using_top_more_efficiently_3.html

>From that page we see that VIRT is the virtual size of the task, which
includes the executable size of the binary (and binaries are never all
loaded in at once, but pages of them are requested as needed), along
with swapped pages, and shared libraries (which are shared usually
with other binaries on the system, so that's an inflated figure
anyway). And it includes data pages (which can be swapped out), and
that's going to be bigger for 64 bit systems, simply because 'int' is
8 bytes.