Thread in start without debugging slower than start with debugging.

Hi All, I am facing a problem as my threads in visual studio wpf is performing slow while using start without debugging. When I use the start within debugging, it is fast. How can I make my threads run faster while using start without debugging? I have did a for loop and stopwatch to record the performance, when using Start as F5 is 5 seconds, then I use Start without debugging as Ctrl+F5 is 7 seconds. I wish to make it faster, can someone provide me a solution?