The stock Apple 5870 in my upgraded Mac Pro 5,1 (really a 4,1 with a single 6 core 3.33) seems to be failing and I'll need to replace it in the near future. I don't/can't pay for an original 5870 replacement and the less expensive 5770 may even make less sense. Here is what I'm looking for: 1) performance similar or better than the 5870. In reality something performing like the 5750 would probably be fine, but I assume not cost efficient at this point? I don't need super high FPS in any sort of gaming scenario. My main uses are Aperture (for a bit more), LightRoom, Photoshop, iMovie, Final Cut Pro and a few other related apps. Obviously it must be rock solid in terms of stability. 2) the capability to drive a 27" Apple Cinema display is absolutely needed. Ideally if it can also drive the speakers over Mdisplay port -- all the better. 3) If the card can also drive a future 4K display -- great! 4) Boot screen is not required -- I don't bootcamp, and even if I decide to a reboot is fine by me. 5) If I can be kind to both my aging MP's power supply and the environment, awesome! Not sure what the best metric is for Bang/Watt, but it would be very cool to make use of better tech to make my graphics card work off of one power lead and not two, like my 5870. I really hate to see that the video card often uses as much power as the entire rest of the computer. So, love to hear your recommendations.