Does PowerShell code run in single thread mode (-sta) run slower?

Hello

I want to start putting some GUI front ends on my utility script/s 

I want to use an approach that will be supported further down the line, therefore I am looking at using WPF instead of Windows Forms.

However I see when incorporating PowerShell code (e.g. System.Management.Automation) in to a WPF application would have to run the code single threaded mode (-sta) 

Therefore my first though it will this mean the code will run slower? as I am assuming the default non single thread mode allows PowerShell to use more than on CPU thread to get its work done, and therefore should be quicker. Unless the above is not related to this but refers to something else?

advise most welcome.

Thanks
Ernie