How do you diagnose processor overusage?

[Nick]

Hi...

MY PROBLEM

The CPU rarely goes below 50% and frequently goes and stays at 100%. To
diagnose a possible problematic device driver, I tried the following:

PROCESS EXPLORER (says...)

SysInternals app "Process Explorer" says that the processor is
overwhelmingly occupied by DPCs and Interrupts.

(MICROSOFT RATTV3)

"Rattv3" displays the response time of drivers. It diagnoses:

- Audio and video "glitches"
- Problems with other devices by overly delaying the execution of other ISRs
and DPCs
- Interference with applications due to over use of CPU time

MICROSOFT RATTV (says...)

Here is the first run. Can someone *capable of interpreting* this please
this help me by picking out a problem driver, based on the execution times?
Your expertise would be greatly appreciated.

http://images.mirrosoft.net/RTTV3_report.mht

Nick

xp pro on SBS domain
Athlon 3200+
1.5 gb PC3200

 

[Pat Garard]

G'Day Nick,

Don't confuse us with facts.

Run Task Manager
Click on the Processes Tab
Do NOT click in the body of the list.
Click on the column header 'CPU' (to sort), wait ...
... and click it again (to sort in reverse).

The process at the top of the list is the one using the most CPU -
what is its Image Name?

 

[Nick]

Hi Pat,

Thanks for your help. Interesting result. With Outlook open, I scroll one
of its windows. This causes Outlook.exe to consume more than 50% of the
processors output. Csrss.exe (the legitimate one) consumes about 20 during
this scrolling.

Otherwise, when idle, System Idle Process consumes > 80% of availability.
If this is a measure of availability, it seems odd that it is listed at the
top of the list of greatest CPU users. When System Idle Process is
dominant, the task manager icon displays it value as the actual CPU usage.

Confusing!

Nick

 

[Pat Garard]

G'Day Nick,

The System Idle Process is a "Claytons" process that "accounts" for the time
the CPU is "executing" nothing - i.e. it has nothing else to do.

Another experiment you can perform (with a lightly loaded system) is to
scroll with the Mouse wheel and compare this with scrolling a page at a
time with the Scrollbar. The constant redraw of the wheel scroll will use
more CPU than the 'one-off' page redraw.

Then try moving the mouse quickly in circles - that will usually consume
5-10% of available CPU.

Then forget about it!!

 

[Nick]

I'm not sure if I understand the experiment. Having tried it, the result
was that wheel scrolling was vastly smoother, though not perfectly smooth.
Drag scrolling was very difficult with a fully occupied processor.

Nick

 

[Pat Garard]

Hi Nick,

(USING TASK MANAGER)
Another experiment you can perform (WITH A LIGHTLY LOADED
SYSTEM) is to scroll with the Mouse wheel and compare this (CPU USAGE)
with scrolling a page at a time with the Scrollbar. The constant redraw of the
wheel scroll will use more CPU than the 'one-off' page redraw.

Then try moving the mouse quickly in circles - that will usually consume
5-10% of available CPU.

Then forget about it!!