I have WPT 2.9 installed on a dedicated box and I am using the AMI test clients. I have been putting a custom front-end on it so I can automate it more easily. Everything was working fine until I set up a few to run hourly. The test were not finishing in a timely manner so they were backing up and the queue grew to over 100 tests. What is the optimal configuration to run say 10 - 20 at the same time on an hourly basis?