when researching about performance counter (using Perfmon of Windows), I have trouble in understanding.
In microsoft site, I found that if CPU usage is high and system/ process queue length counter is > 2 for a continuous time then it is a suspect CPU bottleneck.
However, when searching, I still found an article saying that the system/ process queue length counter is always > 2.
When trying, I found that on my machine, whenever I feel it is slow, the system/ process queue length counter is larger than 2.
But on other machine, although the CPU is not high (<50%), this counter is still over 8 (scale is 1.0)
So, I want to ask, is this counter (system/ process queue length counter) believable to find CPU bottle neck?
Re: Ask about system/ process queue length counter
No, you can't use that number alone to tell you about processor bottlnecks.
The 'explain' text on Perfmon on my system (xp pro, SP2, IIS6) says the same as the Microsoft article but "A sustained processor queue of less than 10 threads per processor is normally acceptable, depending upon the workload." Did you remember to divide the number by the number of processors?
I think the answer is that you need to look at that number in relation to the processor utilisation. If the processor utilisation is less than 80% then I wouldn't worry too much. If your machine is running lots of services then it has lots of threads and it may have more threads queued at the processor.
Similarly in IIS you may not have many in the queue but you might have lots of ASP\reqeusts queued which could also be an indication of a bottleneck.
You need to look at more than just this one number.
Everywhere's within walking distance if you have enough time.