I created a program that allows me to choose how many threads to use to send requests to a web service. But I've noticed the numbers don't add up when done in a certain way. When I open only one copy of my application and select 30 threads to start sending request, in 15 minutes, the request per second is 0.09. But when I open two copies of my application, and select 15 threads for each (so that's 30 total threads), I am able to get more request with a request per second of 0.12. Is it my design or is this just how it is? The more threads you use, the slower it is?