2 ATI Radeon HD 4870 in a Mac Pro 3,1

[3282868]

I have two ATI Radeon HD 4870 graphics cards (One was damaged from shipping my Mac Pro cross country but I was able to get it working again), and someone once stated you could put both in your Mac Pro and connect them ( ? ) to double your graphics capabilities. If this is true, how does one do this as each card needs it's own power and I do not believe the Mac Pro has more power connectors (unless you split the power cables to power both cards) and what would the benefit be, if only using one mini displayport and one DVI port?

 

[Hellhammer]

OS X doesn't support CrossFire so I think you won't get more than possibility of more screens. In Windows CrossFire should work but not sure how it does with Apple GPUs.

You won't get twice as good performance under OS X, I think

 

[3282868]

Ah, crossfire, ok, I forgot the term. Thanks! You're probably right, I'll do some research too.

 

[MacVidCards]

Ah, crossfire, ok, I forgot the term. Thanks! You're probably right, I'll do some research too.

Crossfire will work in Windows, no help at all in OSX.

To enable crossfire, you need both 48xx cards to be in slots with same number of lanes.