Patek uses an all new movement (caliber 324) in it’s new Gondolo Calendrio. Main improvements and modifications to this movement in comparision to other calibers are: higher beat rate ( 28.800 i.s.o. 21.600), new (4 spoke, 4 maselots i.s.o. 2 spoke, 8 maselots) Gyromax balance wheel, advances in wheel toothing geometry for higher rate accuracy.
Here’s the whole article: New Gondolo Calendario 5135