After I added my new SATA drive by using the PERIP port accidentally, my system seemed to become completely unstable. My Thunderbolt PCI-E card in my system is randomly not showing up, my display (also PCI-E) stopped working for a second...
But, everything I've read suggested the PERIP port and the SATA port on the PSU are interchangeable. Is that true or is that only the cables that are interchangeable?