Hey Everyone, Having issues with 10.10.3 update. Supplemental update hasn't helped. Build: Mac Pro 5,1 •16GB ECC DDR3 RAMM •OWC Mercury Accelsior_E2 (Basically Flash Storage) •6TB of SATA II HDD (SATAII instead of III because of over heating issues caused by lack of support for SATA III) •EVGA GeForce GTX980 SuperClocked (Also have a few AMD's available but not on board) •USB 3.0 PCIE card (Generic and cheap but awesome results) •Dell P2715Q 4k Use: •Virtualizing Windows Server Tech Preview and 2012 (Practicing integration with Active Directory) •Running MAC OSX Server and Plex Media Server (OD, Time Machine, Web Server, etc.) •Video Editing •General Business Use Problem: I had a Sapphire 9750 installed when I updated to 10.10.3. The card already had issues so I thought it was the card. I got a replacement card and installed it but this didn't help. I returned the card and ordered an EVGA GTX980 SC and it still didn't work. At this point I begin to understand that Apple screwed me with the 10.10.3 update. Supplemental Update did nothing. Worthless. Troubleshooting Steps: This guy, ME! I made a backup using Carbon Copy Cloner before the update. So I installed a basic AMD card and booted to it after reversing changes by trim enabler (This described here). I booted the Backup Running 10.10.2 and installed CUDA from NVidia and Web Drivers, rebooted and shut it down. I swapped out the cards and proceeded to test the ports. Everything worked under 10.10.2. When I tried all this under 10.10.3 (using the newest web drivers) I still got nothing but a black screen. As of right now I am accessing the 10.10.3 volume by booting it without external graphics card. Any help or guidance would be greatly appreciated.