you right i did read that earlier. And yes I have it set up so my SSD is running OS and the other is just a back upWHY would you want fusion? Your SSD should be the boot drive and the hard disk can be used for data. These 5400RPM drives are really slow, topping out around 100MB/sec however your SSD should run at around 500MB/sec. Aside from that, as has already been said, fusion drives and APFS are not a very good idea. Initially they were not supported at all but that was added later.