How much time does it take?
With a little practice, you should be able to chant each round in approximately 8 minutes, allowing the full 16 rounds to be done in about two hours and fifteen minutes. If you're chanting at high speed, and a round takes only four minutes, you're probably pushing it. The standard that should regulate your japa speed is how clearly you are being able to articulate the Holy Name. One has to be careful not to fall into bad habits, like dropping, slurring or mumbling words. This is a very easy mistake to make, particularly when you're anxious about time. In the beginning, just try to pronounce the words as clearly as possible at a speed that will enable you to get your rounds done within an appropriate amount of time.