Hey all, This is my first new post on this forum. It seems like a great community and I'm having a heck of a time getting this GPU to work. Here is my scenario: My system is a Mac Pro 2,1 with: OSX 10.10.0(thanks Pike!) 2x Quad Core Xeon 3.0GHZ processors 32GB 667 RAM 128GB SSD 750GB 7200RPM HDD 3TB 7200RPM HDD I followed all instructions in the sticky at the top of this forum and am not able to get my Mac to boot to the login screen. I hear the chime, but no output is sent from the GPU. Below is what I have tried: I installed the Web and CUDA drivers while my old Radeon HD 6850 was being used for output. I set flags appropriately before and after installs. I shut down, put in the GTX, and no output upon boot. I went to the nVidia settings in System Preferences and set the driver to nVidia instead of Apple while using my Radeon 6850. I shut down, put in the GTX, and no output upon boot. I plugged in the stock Radeon card into the bottom PCI slot and the GTX into slot 3. The Radeon was properly identified, but the GTX was identified as a 256MB VRAM card. My Mac Pro only has one six pin connector; for now, I've plugged this in to one of the Y 6 pin to 8 pin connectors, and then into the GTX. I have ordered a standard 6 pin to 8 pin connector(NOT A Y CABLE LIKE WHAT CAME WITH THE GTX). Will this resolve my issue, or is this related at all? My understanding is that one 6 pin connector delivers 75W and the PCI-e 1.0 will deliver 75W, for a total of 150W, which should be enough for this card. I am at my wit's end and I really want to get this working, as it is the last piece to the major upgrades I've made to my Mac Pro. Any help will be extremely appreciated. Thank you! EDIT: Just to clarify: I am ok with the lack of Boot Screens with this card. The issue is that the login window never appears and I am not able to access my system due to the complete lack of video output with the GTX 960. Thanks!