Web Server tuning (MSFT)

Link: Balancing threads against overall performance as measured by connections and requests can be difficult. Any time you tune threads, follow-up with overall performance monitoring to see if performance increases or decreases. To determine if you should adjust the thread count, compare the number of threads and the processor time for each thread in the process to the total processor time. If the threads are constantly busy, but are not fully using the processor time, performance may benefit from creating more threads. However, if all the threads are busy and the processors are close to their maximum capacity, you are better off distributing the load across more servers rather than increasing the number of threads