Question about CPU Usage Reporting in XP

I'm looking at a sluggish system: Windows XP SP3 (32-bit), MSI 785GTM-E45, Athlon II 255, 4 GB RAM.

When I look at Task Manager, I frequently see the overall CPU above 60% (sometimes 90%), but the System Idle Process shows 65% or more. I have 67 processes showing, so there's possibly a lot of task switching. But I'm really curious as to what might be using CPU and getting captured in the total "CPU Usage" figure at the bottom of the window, but NOT captured as part of a process in the list.

I thought about paging, but I don't see numbers that are alarming there. At times, I will see very high numbers in the PF Delta (several thousand in a 5 second period).... but that's not what I'm seeing this afternoon. A couple processes that are 250 and 500 respectively.

Over the past 3 months, Windows has reported serious errors on 3 different hard drives, both EIDE and SATA, as well as my CD/DVD drive (EIDE). (S.M.A.R.T. says no errors on the HDD's.) I'm not seeing anything interesting in the event log in recent weeks, though.

Suggestions?

Thanks!!

 

I think getting Process Explorer from Sysinternals would be a good idea for you. I also like System Explorer. For me the only advantage of Task Manager is it shows when a process is Not Responding, whereas those programs unfortunately don't show it.

 

WTF (What's This File) may be of some assistance to you.

 

Seems like to me that there have been numerous mentions of activity in threads lately with svchost.exe using the processor relentlessly. I have looked into this fairly seriously, and, if this is your problem, it seems to be mostly related to Windows updates...

 

I suggest that you first do some maintenance to deal with some of those errors.

For each of your hard drives, go to Properties > Tools > Error Checking - Check Now
and set it to Automatically fix file system errors.
They will be checked when you Reboot.

Then set the paging file to No paging file. Be sure to click Set and then each OK as you exit the dialogs.
After you reboot, reset the paging file on the system drive to System managed size

67 processes is a lot to have running; probably far more than you need.
Check your StartUp Processes and see what can be disabled.
Startup Control Panel Standalone Version is a simple program that works well with XP.

Download Process Explorer as conceptualclarity recommended.

Double click the Process heading twice or select Show Process Tree in the View menu.

Regarding the svchost.exe problem, IF you see that happening, you have to find what process is Dependent on that instance of svchost.exe.
The process tree view can show that.

svchost.exe. What is it?

 

I have been negligent and forgot to thank all of those who posted to this thread.

I followed up on each of the pieces of advice, but had been unable to determine the cause of my problem until I was researching something else and found a tip on an I/O issue that someone had experienced... which had manifested itself as high CPU that could not otherwise be accounted for. It DOES show up in Process Explorer as high CPU on interrupts, but I wasn't savvy enough at the time to understand it.

In following up on that tip, I discovered that my primary IDE channel had reverted from the preferred transfer mode of DMA to PIO. The tip also informed me that the only way to reset a channel from PIO to DMA is to delete the channel and reboot. After a series of several reboots, the Primary IDE Channel was back to DMA and my problems were gone!!

For those who have never investigated DMA vs PIO before, read http://www.ifixit.com/Wiki/Enabling_DMA_Mode_Transfers to get the full explanation of the problem.