All you are showing is a symptom (slow execution, low CPU usage).
Have you used Application Profiling? Have you looked at what other connections are doing?
"50 different configurations" is a sign of desperation... if the application is badly behaved then no amount of fiddling with server options is going to help.
Did you actually read that article in the wiki? The statement that you "have read everything" sounds unlikely... if you had read everything, you would have a lot more information to share... Task Manager is not telling you anything helpful.