Regardless of the advice on other systems, you really need to try the various configs as TOM mentioned. What works for one computer might be all wrong for the next one(and I can see no rhyme or reason). After reading about other folks using 1 less core(than all available), different % settings and Hyperthreading off or on, I tried all possible settings and found what delivered the best performance for me was NOT always the same as what others recommend
I tested with a large session and took note of the cpu meter(at the 64 buffer, just to push things) and whether the session would roll, uninterrupted, and took some notes(yep, with that old analog system of pencil and paper
).