Hi, After few tries at the time I bought my MacPro I wasn't sure if all Nvidia GT 120 have a weird behaviour or only mine. Back then, sometimes I had no screen when I boot on my MacPro with the official Apple GT 120. The MacPro is connected to an Apple Cinema Display 24" LED. In order to have back the screen on my display I had to reboot several time or switch the screen and plug it into my MBP to have the screen back on the MacPro. Because it wasn't my plan to keep this graphic card I didn't paid attention to understand if the issue was coming either from the card, the display or the Mac itself. I sold it. Not having the boot screen those previous days made my nervous so I bought a GT 120 My tower is running with El Capitan the latest version available. I received it yesterday and I was surprised to discover the same kind of behaviour. screen doesn't show up or the MacPro doesn't boot at all. I have the dong and then nothing. If I remove all PCIe cards I have same things - no screen or doesn't boot properly. I had to remove the cards and so without any PCIe cards the MacPro boot fine I was able to control to the computer via ssh or screen share. If I put back the 980ti the MacPro also boot just fine. I don't understand why the GT 120 has this weird comportment with the screen and the MacPro. It was very similar to my other GT 120. Do you know if the GT 120 is knoz to not be fully compatible with the Led Cinema Display? have anyone already heard about this weird behaviour and how to fix it? Thanks!