I am going to buy a new pc and was wondering how many fans i can connect to a Asus Prime z370-a motherboard. one of them will be used to power my CPU cooler, so how many do i have left?
Using a discrete control board, as many as you cram into the case; and in the answer above, you can use splitters to run 2-3 fans off of each chassis fan header.
You can use a splitter on the cpu header as well, but assuming a pwm fan, the controller would get confused and not regulate the fan speed correctly.
Many discrete control boards have 8-12 fan headers.