Each row of the machine produces around 50,000 cobblestones per hour for a total of over 150,000 per hour when all rows are activated. It has a 99% drop rate. The reason it's not 100% is that sometimes cobblestone can get caught in the water between the pumps, and I haven't found a solution yet to fix this problem without redesigning the machine. The RPM the machine requires is 0.5 RPM, and the machine only uses 20 SU, which is less than a quarter of a water wheel. How can the machine run at such low RPMs? Well, first of all, the pumps don't require much speed because all they need to do is show the pumping particles and the mechanical bearing doesn't need much speed because all it's doing is picking up and placing back down the sails, resulting in an extremely efficient cobble gen.