Chapter 76 in the Conversations of Rav Nachman of Breslov says that one ought to learn as fast as possible. at first it is brought there that he said that all one needs is to say the words in order and to go on. but at the end of that chapter he said to learn as fast as possible. the meaning seems clear that he was not worried if one understands or not. This is mentioned in the gemara but in that chapter the idea is taken to a degree that most people find untenable. Yet those same people that refuse this advice, do you think they go on to learn in depth? Not usually. Rather they give up on the learning. I must say that this kind of learning helped me very much when I was at the polytechnic institute of N.Y.U. doing physics. and there was tremendous pressure on me to understand the learning and yet I found this method to be of enormous value. but I must add, that after I did the fact learning, I went back over the material and reviewed it again and again.