What is the System Idle Process and why is it using most of the CPU?

Hi
The Idle Process can kick in when you are engaged in when you are using Movie Making software and are downloading or writing video causing you to lose or get distorted clips or frames. To get around this you can deliberately start the Idle Process so that it effectively gets it out of the way and won't start up in the middle of your movie making. You can also use a little program called "End It All" which also helps, but thats a different thread.
David

Simon said: "which raises the question of what the CPU would be doing that would use power if the OS *didn't* continually issue these HLT commands."

Adding 0 to 0. Repeatedly. :)

Actually, that's a joke. What it would do is check over and over again if anything's happening, like a key being pressed or the like. Read http://en.wikipedia.org/wiki/Busy_waiting (and http://en.wikipedia.org/wiki/HLT while you're at it).

Also, thanks for pushing me to research this :)

Sometimes my machine is running idle and it cannot be interrupted. That is, the idle process is too busy to notice keystrokes and mouse clicks.

Leo, do you know why this is happening?

I once read something about WinXp automatically moving files about, a kind of optimisation. When I can't interrupt the idle process there is certainly a lot of disk processing (I can hear the heads thrashing). I haven't been able to find the information about automatic file positioning again and sometimes wondering if it was a figment of my imagination.

The point seems to be that users expectations are that the SIP should not take over the machine, but it does, interferring with the usefulness of the computer. There have been many times for me when a program has appeared to have crashed when in fact the computer is just busy doing the SIP. If the SIP is housekeeping processes and commands to keep the processor occupied during periods when programs are inactive then as soon as a program requires the CPU, the SIP should be suspended. So either the SIP has been badly programmed or it is more than the computer sorting itself out. Either way this is very frustrating to users and a way to control the SIP would be really welcome.

On my computer i found the same thing, but while transferring a massive 120 gb folder from partition to partition. Needless to say it is deadly slow, should,nt the processor consider that an opportunity to maximize the cpu to decrease time? Or did i miss something here, =)

Leo, I understand what you are saying about SIP not interfering by definition, or by design is probably better. But what Hawkins, Webb, and Milton are saying is true. In practice, I have often noticed momentary hangs in the application I'm working with when SIP kicks in (this is XP SP2). Whatever the intent, SIP does in fact interfere. What is needed, as Milton says, is user control of this feature.

I read the above article and I understand the virtual thumb twiddling bit SIP doesn't stop when I try to start another program. Is it that once it starts, it must finish the SIP first? Is this process only characteristic of Windows?

This is one of the few posted answers that uses "resources" instead of "usage" or "processing" But may still leave some in the dark. The CPU column next to "Image Name" in task manager(as in posted pic) is NOT the cpu "Usage" it refers to cycles to the processor(instructions that let it know whats goin on, on the system - kinda like the dispatcher of your local taxi company) In this case the System Idle gets all the dispatcher attention when your system is doing nothing. Although it cant be seen on the edited posted pic, at the bottome of task manager is the ACTUAL cpu "USAGE" When the cpu "USAGE" goes up the Idle "CYCLES" go down and vise versa. So when the "CYCLES"(shown in pic) are in the 90's your cpu "USAGE" should be low 0-10%. If you are seeing both #'s high there may be other issues. As far as some of the post with jerkiness I beleive that is an XP IDE problem itself. I have used 2k til 08 when forced to upgrade due to newer hardware and have had that problem as well, EVEN when my actual cpu "USAGE" has been under 10%.
In closing the high "CYCLES" are normal on SysIdle if you have constant maxed "USAGE" (bottom of task manager)then you have something goin on but the high "Cycles" arent it.

My "system idle process" has been running from 95 to 99 since Friday....5 days....and I have just been able to sign on the internet tonight (Tuesday night). Don't understand this.....and even though I can sign onto the internet now, this "thing" still seems to control what I can and cannot do.....Richard

Leo, don't worry these guys will never get it.

The System Idle Process is not actually a process, it's a representation of the CPU that is not being used.

I.E. You have firefox running at 5% cpu usage constantly and nothing else is above 0% the System Idle Process will read 95% usage because it's the inverse of the amount being used... it's not actually using 95% of your CPU (it does nothing and serves no purpose except to show what is not being used).

The problem most people are referring to is more than likely to be Intel SpeedStep or AMD's Cool n Quiet technology, both of which throttle the CPU clock speed (and sometimes voltage) when the computer is inactive (idle) if enabled.