Post a logfile from a streaming or recording session at least 30 seconds in length, and we'll be able to take a look at what's happening on the back end.
There is no such thing as 'best settings', as systems and situations differ wildly. That said, Apex is well-known to be a massive GPU hog. We'll be able to tell more with a proper logfile.
If you don't know how to provide one, there is a pinned topic at the top of this forum with information on how to do so.