Using the Pentium performance counters, we also compared the software interrupt-version of AFPA with the threaded version of AFPA on Windows 2000. For 64 byte files the software interrupt version was 12% faster than the threaded version (10,321 versus 9,209 requests per second). This closely matches the difference in the number of instructions executed. This difference corresponds to the overhead of queueing/dequeuing work items and scheduling the thread.