i have a spare 1tb PCI-SSD blade from an new Mac Pro purchase and would like to use it in a new late 2015 Retina iMac. I was considering getting a 1tb Fusion Drive and using my Blade as the primary HD, but I don't know if it's possible.I've looked at guides about upgrading the Fusion Drive but not about upgrading the PCI-SSD hardware and using it for the OS. Or maybe I purchase the 256gb SSD instead of the fusion drive? I'm fine with either the fusion HD or SSD, but my primary question revolves around using my spare 1tb PCI-SSD as the primary partition. Any advice would be appreciated.