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Running Windows XP on a AMD dual core processor. Occasionally after booting, logging on, and letting things settle down, the Task Manager shows on the graph that one processor is over 90% busy. Yet when one looks at processes running, system idle is at running around 98%. On performance graphs, the CPU usage bar shows as red with tiny amount of green. Only one user is logged on.
It is as though there is a rogue task that task manager doesn't know about when showing the processes, but does know about when showing the performance graphs.
I have seen this several times. What I've done in the past is reboot the system, and the problem/anomaly was no longer present. A log-off / log-on did not get rid of the rogue usage.
I have not explored if the issue is triggered by a long delay from power-up to log-on.
System seems clean on anti-virus scans. Network activity is zero.
Any ideas as to what might be happening?
Process Explorer provided additional information. System Idle Process dropped to just under 50%. About 30 to 35% of CPU for Hardware Interrupts (?!) and 8 to 12% showing as Deferred Procedure calls. – None – 2009-10-21T21:23:26.717
Ran RATTV3. nvata.sys seemed to have high numbers with DPC Total 33 million in 3 runs, next highest at 35k. Rebooted system, problem now not present. Thought I could do a compare, but the histogram is cumulative. RATTV3 says after 13 runs, nvata.sys at 42 million. I would guess almost all of that was pre-reboot. – None – 2009-10-21T21:24:21.707
Unsurprisingly, it's a video card driver. Make sure you've got the latest stable version of the drivers. – None – 2009-10-22T08:45:05.507
I refreshed the drivers on Oct 21 (now at 6.14.11.9107 AKA 191.07). So far no recurrence. – refactor – 2009-10-27T15:01:15.350
Its back. RAATV3 shows nvata is at it again. 191.07 is still current set of nvidia drivers. – refactor – 2009-11-06T00:30:41.233