Cemu

In Pikmin 3, whenever you are about to win the (splitscreen) bingo battle mode or may potentially win, there is an effect that causes the viewport of the winning side to rapidly and smoothly increase/decrease in size. On console, this effect runs seamlessly at full speed but on CEMU, there is massive slowdown (sub 15fps) aswell as occasional black 3D rendering. This was tested on 1.15.8 with a graphics pack that sets the resolution to 4k (bug occurs with or without, althougth doesn't slow down quite as much at native res). My specs are an i5 7500 and a GTX 1070 and 8GB of 2400MHZ DDR4. I will test 1.15.9 when it goes public.