While you are tuning the application, it is important to identify if a setting is the factor enhancing the performance or not, and thus identify it as important or not.
If you change multiple settings for a single run, you will not be able to say which setting triggered a change, or you can even neutralize a good setting by using another bad one and missing an optimization factor.
Resist the temptation to change everything at the same time, and try to keep a scientific approach, changing a single setting at a time.
