The FAA written test is:
FAA TestTime Private Pilot Test2.5 hours Instrument Rating Test2.5 hours Commercial Pilot Test3.0 hours Flight Instructor Test2.5 hours Drone Pilot Test2.0 hours Drone Pilot Test (recurrent)1.5 hours
Most folks do not need the full amount of time to complete the FAA test, however, there is no penalty or advantage to finishing early.  Your score is based solely on the questions you get right and wrong.