I have a Mac Pro 5,1 with a stock ATI Radeon HD 5770. I recently purchased another genuine Apple (not Apple-flashed) ATI Radeon HD 5770 and installed it in the Mac Pro. Both cards are working fully and independently on Yosemite and on Windows 7. I want to now set up the two cards using Crossfire to use for both Mac and Windows (dual boot). My questions: 1. Is it possible to crossfire two stock genuine Apple ATI Radeon HD 5770? Both cards have fingers that are seemingly for the Crossfire bridge connectors. 2. Where do I buy the Crossfire bridge connectors? Does ATI or Apple sell the bridge connectors for 5770? Is the bridge connector different for the different models? 3. I am using the BootCamp driver 5.1.5621 that has built-in ATI Catalyst driver support. Is this sufficient to run Crossfire? I already searched the forum and was unable to find the relevant threads. The few threads that spoke on Crossfire gave no conclusive tips on using the HD 5770 specifically. Confused. Please help!