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Re: Pros/Cons Kde vs Gnome?



"Daniel B." <REMOVEdanielTHIS@fgm.com> said on Fri, 18 Jun 2004 10:22:43 -0400:
> Micha Feigin wrote:
> 
> > ...
> > and they do require more cpu, eye candy takes cpu power to draw (either
> > real cpu or graphic card cpu, either way, battery power). 
> 
> What fraction of CPUs these days can switch to low-power mode when
> idling and what fraction use the same amount of power regardless of
> whether they're idling or executing instructions?

For the latter question: none.

A transistor dissipates heat when it is in the process of switching on
or off - when it is fully on or fully off, there is very little
current flowing. Which is partly why modern CPUs run so hot - because
they switch so fast (the other reason is that there are so many more
transistors -- but of course they are smaller too).

So, if a programming is sitting there spinning, then depending on what
it's doing (in order: maybe rendering millions of polygons on the
video chip, maybe doing FPU, reading and writing to RAM (this involves
lots of cache action, and talking on the external bus, which
presumably requires far more current that what is involved internally
within the CPU), or just sitting on a busyloop), then there are going
to be varying amount of transistors switching.

If the only process running is the idle process, doing hlt()
instructions in a loop, then there are bugger all transistors doing
anything, so less power gets consumed.

AFAIK, all modern i386 (AMD, Intel, etc) CPUs at least have a htl()
instruction.

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