CPU usage % mismatch

[Geoff Walker]

Windows XP with all latest updates and patches, running on
1 GHz Dell Inspiron laptop. Upgraded from Win 2000 a few
months ago.

Sometimes when I restart the system, the CPU Usage
displayed by Task Manager doesn't match the totals in the
Process list. For example, the CPU Usage may show 18%
while the System Idle Process shows 99%. The performance
graph also shows CPU Usage at 18%. The graph shows most
(95%) of the 18% CPU usage to be kernel time. Although
there is no visible process consuming CPU cycles, there is
clearly something running at high priority because the
cursor movement is jerky. If I reboot enough times,
eventually I hit one where the problem isn't present (that
is, the numbers match, for example, CPU Usage is 2% and
System Idle Process is 98%). I've searched the Knowledge
Base and can't find any mention of a problem like this.
Any ideas on how to find out what's wrong?

 

[Tom Swift]

I can't address the specifics of your question, but please keep in mind that
the CPU Usage displayed by Task Manager is only a sampling and is accurate
enough for the uses intended. You can expect it to be least accurate during
bootup, where the processor is being extensively used. If you want an exact
real-time calculation, there may be third-party software that can help you.

Tom Swift

 

[Geoff Walker]

This problem isn't a boot-time issue, it is present all
the time. I've looked in the system error logs, done a
virus scan, checked the device list, but I can't find any
clues. I'm using Task Manager only as a diagnostic aid. I
tried setting the update speed in Task Manager to "high"
[0.5 seconds]; at this setting, it shows a short burst of
66% CPU usage exactly every two seconds. The usage is all
kernel. In between bursts the CPU usage is 2% (normal).
I've tried killing every process that Task Manager will
let me kill, but the problem remains. It's annoying
because the cursor stops moving momentarily every two
seconds (whenever the burst of CPU activity is taking
place).