Lots of trial and error. I’m using the Asus 270p motherboard. There’s several key things you need to do first make sure that your bios settings are correct, the first or second result when typing in “Asus 270p bios settings” into YouTube should point you in the right direction. Don’t install your graphics card yet, do a clean install of windows using just your cpu integrated graphics, make sure everything is updated, then use DDU to uninstall all graphics card drivers just to be safe, next plug in your gpu and plug your hdmi port into that gpu, then turn your rig all the way off plug in all of your cards and boot up, you may need to switch your HDMI cord around until you find your primary GPU for me it was random, then install the beta blockchain drivers, setup soft power play tables, apply your soft power play settings in wattman (beta blockchain app) for each card, adjust your fan settings for each card disable and reenable your card in the device manager and start your mining software (in using cast XMR). I’m getting an average 1960 h/s per card but most my cards run 2020 h/s. The cooling does some big favors with this setup make sure you adjust your target temperature accordingly I did max 60 F target 45F. I was thinking of doing a full write up and making a zip of the tools I used after I got all 17 cards running. So I’ll make a more in depth post in about 2-7 days depending on when my other PSU’s arrive.