Need help! Crossfire with ATI Radeon HD 5770 x2 on MacPro 5,1

[timidhermit]

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!

 

[IowaLynn]

FCP-X and Motion are written to make use of dual AMDs and test results by www.barefeats.com

 

[Surrat]

I may be wrong here, but from what I understand:

OSX will use multiple vid cards, but not as crossfire. They are seperate cards, like one for video, and one for compute functions.

Windows should be able to use them separately or in crossfire like for games.

I would also like to point out, that the apple oem 5870 was just as powerful as two 5770's in crossfire.
Another point is if your using 10.3, MVC has nvidia GTX 750 cards that use maxwell gpu's, are faster than a 5870, and completely up to date on features.

I would recommend selling both the 5770's you have on ebay, since there is still good demand and pricing. Use the money to either get an apple 5870, sapphire 7950 mac edition, or nvidia GTX 750 from MVC.

 

[timidhermit]

Thanks for the suggestion.

For other reasons I shall not explain here, I prefer to keep both of the ATI Radeon 5770 cards.

I can live with using Crossfire in only Windows, so I only game in Windows anyway.

What about my question of getting the Crossfire connector? Is there an Apple one I should get? An ATI branded "official" one? Or others?

Once I hooked both cards to the connector, what else do I need to do? And how do I test it to know that the Crossfire is working?

 

[Surrat]

I would ask in the windows section of this forum for advice on ATI drivers and how to enable crossfire in them.

I have nvidia, so cant give you specifics.

 

[timidhermit]

Thanks, Surrat.

To moderator: Please close this thread.