heat, idle, and busy loop

[Shi Jin]

Hi there,

I have been having this question in mind for long a time: what is going on
with the system's idle process?
I think it is just a busy loop like
while(1)
{
}

Somebody on the newsgroup said that the CPU(at least x86) hat have a simple
power saving mode that can be used in the idle loop to sleep the processor
until the next interrupt.
This is great.

But when I write a simple c code containing the busy loop above, I see the
CPU usage 100% by a stupid loop program.
My Dell PC fan starts to make a loud noise. Obviously, there is more heat
generated than a system idle.

I don't understand what is exactly the difference between the OS's idle loop
and my stupid loop.
Could you please me explain this?
Thanks a lot
Shi

 

[Skeleton Man]

I have been having this question in mind for long a time: what is going on

with the system's idle process?

http://www.liutilities.com/products/wintaskspro/processlibrary/System Idle
%20Process/

"the System Idle Process is not a process, more a counter which is displayed
in WinTasks used for measuring how much idle time the CPU is having at any
particular time. This counter will display how much CPU Resources, as a
percentage are 'idle' and available for use."

Regards,
Chris