Tulku Urgyen Rinpoche (1920–1996) on the differences between Mahamudra and Dzogchen — and the relationship between them.
In Mahamudra, you are introduced to mind and then you train with awareness. The practice is mixed with mind until reaching nonmeditation. Then the practice is only rigpa, the ultimate view. In one-pointedness and simplicity, you exert lots of mental effort, through which fixation greatly reduces and obscurations are cast away. It is like peeling off different layers of corn; first one is peeled, then the next and the next. In Dzogchen, from the very beginning you are introduced to nonmeditation, nondistraction.
According to the words of Künkhyen Tsele Rinpoche, also called Tsele Natsok Rangdröl:
Mahamudra and Dzogchen
differ in words but not in meaning.
The only difference is that Mahamudra stresses mindfulness
while Dzogchen relaxes within awareness. more...