Total DPCs Queued/sec is the combined rate at which deferred procedure calls (DPCs) are added to the DPC queue of all processors ...

Total DPCs Queued/sec is the combined rate at which deferred procedure calls (DPCs) are added to the DPC queue of all processors on the computer.  (DPCs are interrupts that run at a lower priority than standard interrupts). Each processor has its own DPC queue.  This counter measures the rate at which DPCs are added to the queue, not the number of DPCs in the queue.  It is the sum of Processor: DPCs Queued/sec for all processors on the computer, divided by the number of processors.  This counter displays the difference between the values observed in the last two samples, divided by the duration of the sample interval.