I was doing some experiment in finding the best limit/setting for the application queue limit in IIS....and here goes the results( I found this at Administrators pocket guide for IIS 6)
Formula for calculation :
Application pool Queue Length limit = ( Available memory in MB * number of processors * 10 ) / ( total number ofapplication pools).
for eg: let us say that i have 10 applications ( i mean 10 application pool, one to each application) and available memory 500 MB, and machine has Core 2 duo processor , then the good number for Application queue length limit is500 * 2 * 10 / 10 = 1000
A small twist, let us say your machine has only one application in the previous case, then you shouldnt use the above formula for calculation If you use you will go for a toss by setting 10000
I hope this helps!.