Dear all, I have build a mac pro some years ago (June 2012) asis: Initial Mac OS version: Mavericks Motherboard: Gigabyte Z77X-UD5H (initially F4) Graphic Card: Msi GeForce GTX 660Ti 24 Mbytes of Ram Three monitors: Dell 2x UltraSharp 30 inches (U3011) and later on an extra Dell UltraSharp U3415W 34-Inch Curved because it was not possible to find another 39 inches :-/ What ever it was functioning perfectly All the updates of Mac OS were perfect and I update my system Later-2016 with Sierra and Clover. Current version 10.12.x I wanted to upgrade to High Sierra as on may MacBook Pro 15 2018 but the graphical card was not supported. Some days ago (maybe due to high temperature of the current Summer !?) one screen died out and came back after a while... It's strange. I bought a new graphical card Gigabyte Geforce GTX 1060 2 GB. After switching to the new graphical card I encounter the following problems: 1) At boot level it was not possible to enter into the Bios. So I've update the initial F4 Bios to F14 and I was able to resolve that issue. 2) After Clover appears, I let the system continuing to boot BUT I encountered a Panic Black Screen.... :-/ As it's not a fresh installation, could someone help me to explain all necessary steps to have my system working with this NEW graphical card? PS To avoid multiple potential problems, I've connected only ONE screen and using the DVI connector. Thank you very much in advance to you !