That's incorrect. The seconds hand moves 6 times in one second on my 7S26 movement (21,600 bph). On a modern Rolex, it would move 8 times in one second. You can check this with a high speed camera (such as the one in the iPhone 6). Nonetheless, there are vastly superior mechanical drives out there that are continuous (Seiko Spring Drive for example).
Old Rolex tick 3 times per second on 6 beats/second balance wheel movements, and modern Rolex do 4 ticks per second on 8 beats per second movement.