CPU—Name of the processor for which statistical information is gathered.
Interrupts/sec—Average number of hardware interrupts the processor is receiving and servicing in each second, it does not include Deferred Procedure Calls or DPCs, which are counted separately. This value is an indirect indicator of the activity of devices that generate interrupts, such as the system clock, the mouse, disk drivers, data communication lines, network interface cards and other peripheral devices. These devices normally interrupt the processor when they have completed a task or require attention. Normal thread execution is suspended during interrupts. Most system clocks interrupt the processor every 10 ms, creating a background of interrupt activity. This counter displays the difference between the values observed in the last two samples, divided by the duration of the sample interval.
% User CPU Time—Percentage of non-idle processor time spent in user mode. (User mode is a restricted processing mode designed for applications, environment subsystems, and integral subsystems. The alternative, privileged mode, is designed for OS components and allows direct access to hardware and all memory. The OS switches application threads to privileged mode to access operating system services.) This counter displays the average busy time as a percentage of the sample time.
% Privileged CPU Time—Percentage of non-idle processor time spent in privileged mode. (Privileged mode is a processing mode designed for operating system components and hardware-manipulating drivers. It allows direct access to hardware and all memory. The alternative, user mode, is a restricted processing mode designed for applications, environment subsystems, and integral subsystems. The operating system switches application threads to privileged mode to access operating system services.) % Privileged CPU Time includes time servicing interrupts and DPCs. A high rate of privileged time might be attributable to many interrupts generated by a failing device. This counter displays the average busy time as a percentage of the sample time.
% DPC Time—Percentage of time that the processor spent receiving and servicing deferred procedure calls (DPCs) during the sample interval. (DPCs are interrupts that run at a lower priority than standard interrupts). % DPC Time is a component of % Privileged Time because DPCs are executed in privileged mode. They are counted separately and are not a component of the interrupt counters. This counter displays the average busy time as a percentage of the sample time.
% Interrupt Time—Percentage of time the processor spent receiving and servicing hardware interrupts during the sample interval. This value is an indirect indicator of the activity of devices that generate interrupts, such as the system clock, the mouse, disk drivers, data communication lines, network interface cards and other peripheral devices. These devices normally interrupt the processor when they have completed a task or require attention. Normal thread execution is suspended during interrupts. Most system clocks interrupt the processor every 10 milliseconds, creating a background of interrupt activity. This counter displays the average busy time as a percentage of the sample time.
% CPU Time (Thresholds Supported)—Percentage of time that the processor is executing a non-idle thread. Designed as a primary indicator of processor activity, this counter is calculated by measuring the time that the processor spends executing the thread of the idle process in each sample interval, and subtracting that value from 100%. (Each processor has an idle thread, that consumes cycles when no other threads are ready to run.) It can be viewed as the percentage of the sample interval spent doing useful work. This counter displays the average percentage of busy time observed during the sample interval. It is calculated by monitoring the time, the service was inactive, and then subtracting that value from 100%.