High thread counts aren't an issues usually and just reflects the load on the server , e.g parrallelism/ large number of users etc but when you have a large number of thread in suspended state it usually indicates an issue with another part of the system. Basically a thread is suspended when it reaches the cpu ready for work but ends up not having all the data pages or some other resources needed to complete the job , at this point the CPU suspends the thread and kicks it out of the queue until its ready. Check the number of sessions and requests per second. Also monitor disk and memory utilization to see if any alarms go off.