I have a 2012 MacPro with (2) ATI 5770 Graphics Cards and (2) 512 Samsung SSDs in an Apricorn PCI Card. I am currently running El Capitain from one of the SSDs and the other SSD is empty. I am thinking of maybe installing Mojave on the 2nd empty SSD so that I can start running the latest Adobe CC Apps. What would be the procedure to do what I am considering? Any known downsides? I would like to do a Clean Install vs Upgrade to hopefully get rid of some gremlins.