[wsmacl]

I am using a P4 2.8ghz system with 512 RAM and Windows XP SP2. I do run a secure computer (AVG on and updated, Zone Alarm, Spybot's Tea Timer, Win Patrol, AdAware & Spybot run regularly, occasionally I double check things at PandaScan online). I am on a DSL connection behind a router. Never had any revealed spyware or virus problems (other than tracking cookies).

At times my CPU usage shoots up to a high percentage (90 - 100%, occasionally dropping slightly) and remains there indefinitely. Here is the puzzling part - when I check the list of processes (sorted by CPU) the only number over 5% is System Idle Process. In other words the sorted list will have System Idle Process using 90% or more (which should be "unused") but at the same time the CPU Usage at the bottom is at or near 100%. How can this happen? Can there be a hidden program using CPU time? Could it be a rootkit? Hardware problem?

This has been very hard to diagnose because while it shows up regularly, it does not show up all the time. I have thought it solved several times only to have it show up again. Here are what might be related factors ...

It most often happens shortly after booting up. Within a minute or less of the last programs loading CPU spikes and remains high.

If I quickly "Engage Internet lock" (in Zone Alarm) just after booting it does NOT occur. Even if I un-engage the internet lock just a minute later.

It does not always happen after boot-up. This is frustrating because I have tried disabling some startup programs (Skype, IP Phone Center (works with Skype and a cordless phone), TeaTimer) and thought the problem was resolved only to have it occur again later.

It will occasionally occur at some random point during use (or non-use). When it does this it sometimes will only run up to 60-70% CPU and remain there (again with nothing other than System Idle Process over 5%).

It does NOT seem to slow down my system much. Which is odd considering it is running at or near 100% CPU. Occasionally I will notice a slow down, but not consistently and not the kind of slow down one would expect with 100% CPU.

If, for example, I start a program while watching the processes list, the program will grab it's share of CPU and the System Idle Process will go down (as one would expect), but the total CPU % remains at or near 100%.

Anyone seen something like this before? I did search the forum for this, but could not find a similar problem. Thanks for any help.

[Dan O]

I have seen the problem being related to Recent Document historyand Internet Cache. So I recommend you flush both.

To clear Internet Cache completely open IE and select Internet Options, and General Tab. Then Select Delete for Browsing History.

To Clear "My Recent Documents" see: http://support.microsoft.com/kb/307875

[wsmacl]

Thanks.

Seems a bit odd to be related to those (esp. recent document history), but then again the whole problem seems a bit odd. Will try and see what happens.

Regards,
Scott

Anyone else?

[WhitPhil]

Download and run Process Explorer and see if it helps any?

[wsmacl]

Thanks folks for the suggestions. The problem has not occurred for several days now. It may have been the internet cache or recently used files, or maybe not. It had not occurred for a couple of boots before I emptied those lists - so it perhaps was resolved then, or perhaps deleting the lists was what in fact cured it.

in any case, it seems (cross my fingers) to be resolved. I'll be back if it shows up again.

Regards,
Scott

[Blackmirror]

Originally Posted by wsmacl

Thanks folks for the suggestions. The problem has not occurred for several days now. It may have been the internet cache or recently used files, or maybe not. It had not occurred for a couple of boots before I emptied those lists - so it perhaps was resolved then, or perhaps deleting the lists was what in fact cured it.

in any case, it seems (cross my fingers) to be resolved. I'll be back if it shows up again.

Regards,
Scott

check your internet cache size and set it at 50-60 mb
tools internet options and settings and delete files and cookies on a regular basis...

[Dan O]

Thanks for the feedback. I will mark your thread solved.

[wsmacl]

The problem is occurring again. I have recently cleared the temp. internet files (which I have limited to 50mb), along with cookies and recent document list.

At times when it happens, at first there is very high useage by TeaTimer or SVCHOST, but then that goes down, leaving CPU useage high, but system idle process at 98% or so.

Any other ideas? Anyone else seen this?

Thanks,
Scott

[Frank4d]

Check the box for "Show processes from all users". Something could be running in the Administrator or other hidden account.

[wsmacl]

Good thought. But I already have that checked. Thanks!

Scott

[wsmacl]

OK, I figured something else out. Using Process Explorer I found that it seems that the cycles are being used by Hardware Interrupts. Is this related to IRQs? Could it be an IRQ conflict? Hardware failure somewhere?
Scott

[wsmacl]

OK. I searched the threads based on the new info above and found my problem. My IDE driver (for one of my CD drives) was in PIO mode. I switched it back to DMA and the problem is resolved. I will have to keep an eye on hings to see if I have to reinstall the ide drivers or if the one thing I did resolved things completely. Thanks!
Scott

[jack213]

Hey Scott,

Where do you see and change the CD Drive mode? I've been having occasional problems with my CD/DVD combo + I wonder if that's the cause.

[wsmacl]

Control Panel > System > Hardware tab > Device Manager. Look for the IDE controllers and click on the plus to open that up. Right click on the IDE channel you are interested in and click Properties. You will find the transfer mode under the advanced properties tab.

I can't tell you more than tht because I don't fully understand it myself. Iread another thread which suggested this as a possible cause of high CPU useage by Hardware interrupts. Evidently errors/problems can cause windows to swich the transfer mode back to a slower mode - which in my case was causing excessive requests and eating up CPU cycles.

I have no idea if this would help you - but in any case there it is.

Regards,
Scott

[wsmacl]

Update on this problem. It was NOT the CD Drive it seems. Turns out that it was a router problem. I had a wireless router (assigned a permanent ip address) attached to a router/DSL modem which was the DCHP server. There were three PCs connected to these two routers, each with a shared directory that was mapped on the others as a network drive. I noticed that I was having problems connecting to the other computer's shared drives. When I eliminated the second router and began using a single wireless router/DSL modem the problem was resolved.
I still do see SVCHOST take up a goodly bit of CPU cycles, but it just occurs shortly after starting up and it lasts only for a minute or so. I assume this has something to do with setting itself up on the home network. When it kept on using up CPU cycles previously, perhaps it was not being able to set itself up properly.
Anyway, the case is still solved, but I wanted to put this update in for any who might find this thread via a search.
Thanks to all who helped.