Total Interrupts/sec is the combined rate of hardware interrupts received and serviced by all processors on the computer ...

Total Interrupts/sec is the combined rate of hardware interrupts received and serviced by all processors on the computer It is the sum of Processor: Interrupts/sec for all processors, and divided by the number of processors, and is measured in numbers of interrupts.  It does not include DPCs, which are counted separately.  This value is an indirect indicator of the activity of devices that generate interrupts, such as the system timer, 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 difference between the values observed in the last two samples, divided by the duration of the sample interval.