I believe the general consensus is 8 cards with Asus z270-p and 9 cards with the z270-a. I recommend using linux distros for more than 8 cards. There are btc specific b250,b350, h81 and h110 mobos, but the prices are heavily inflated if they are not sold out.
i hardly use Linux, last time i touch it was like 15 years ago lol, any link that can help me setup Linux system for mining? or i hear the the simple mining os?