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

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.

You and some programing book may say it's doing nothing/something, but often a system gets a bug (we'll say) that gets it rollig out of control.
Whatever the "reason" is, you guys have not had the issue some of these folks are talking about. the system idle process does NOT stop running for many people and it slows the heck out of everything. One guy said it was days b-4 he could even get on line. once it took over an hour for me to even get to the shut down window. Now mine is stuck @ a high # again and I don't remember how to fix it.

I did a search because I was under the same idea, that the system idle process was killing my ability to work. I have a feeling that based on the new info here (from Leo) and the complaints that I was right in my first idea.
The slowdows are the result of either system restore files being written, the hard drive trying to clean up swap files and rewriting or closing files, or both depending on when they take place. I think the system backup is growing too large and maybe the way to stop it, is to make sure the computer is running right and turn off the system restore so it dumps the huge files, then restore it so it can start over.
I hate waiting 12 minutes on startup because the hd is wigging and wigging though the processor and system idle show nothing is happening.
Bill

my systeam ideal prosses sometimes just randomly comes on and when it does i cant do anything ex:im playing a game then that comes on and i start laging so bad that i can hardly move my mouse. but when its not running my computer is really fast it makes me so mad xD btw its running right now wich is why my typing is so bad -.-

Having read most of the comments above, I get what system idle is all about and have never had an issue with it, until now. I never considered it to be a problem for the reasons Leo, and others elsewhere, have mentioned, but what they don't answer is, if while system idle is showing 95% etc and the system going mad with activity why it slows everything else to a crawl? What is it doing? Scenario:- Desktop doing nothing, everything fine, 95% ish system idle, open a web page, activity as expected and fine, I accept once the page is open for the system to then become bored and become idle but not for it to suddenly go mad with activity and thus prevent me from having a nice smooth system, go to open excel or anything else, forget it, cpu far too busy :-( So my question, which gets ignored or skirted around is, [edited] is it doing to stop me from using my pc and why doesn't it recognise that i'm attempting to actually use the god damn thing and therefore the system should no longer be 'idle' and do what I want it to do???? or one day it WILL have a major argument with a hammer, and we all know who the winner will be :-)

Does it effect the temperature of the processor? i am using AMD athlon 64X2 dualcore and its temperature is rising to 42 and 36...
Should i be really bothered?

The more time your computer spends in the "idle" process, the more time the CPU is doing nothing. That tends to run cooler.

19-Nov-2009