Setting up 3 displays on Mac Pro with Radeon 5570

For tha 5x70 cards you should read these:

Mac Pro (Early 2009), Mac Pro (Mid 2010): Supported display configurations

Mac Pro (Mid 2010), Mac Pro (Early 2009): Issues with three displays and multiple DVI, HDMI connections

The general gist of these articles is that you need two active adapters to run thee monitors on 5x70 cards.

If you use DVI monitors and any of them have resolutions less than 1920 x 1200 then you can use single link active adapters. The "AMD Eyefinity Validated Dongles" chart shows some active (and passive) adapters that are acceptable. For example of a single link DVI active adapter is the Accell B087B-006B. An example of a dual link DVI active adapter would be the one from monoprice.com if you need to connect monitors with a resolution greater than 1920 x 1200.

Here's a good explaination of what's going in here and why you need two active adapters on these cards:

Active vs. Passive Displayport adapters *the truth*

I am not sure what to suggest for you. I'll tell you what I have in my somewhat different setup on my 5870 card.

1. Mini-displayport to 27" apple display.

2. Mini-displayport to VGA adapter (qualifies as active) to a 17" VGA display.

3. DVI and optical to the following converter (also qualifies as active)

DVI & S/PDIF Digital Coax/Optical Toslink Audio to HDMI® Converter

So I have the requirements on the card using two active adapters.

Your setup is a problem. I don't know what to suggest. You could use the same TV setup I have to get one of the two active adapter requirements. That leaves the remaining mini-displayport connection. I don't know what to suggest there. You could see if you could "get away with" just plugging it in and see what happens. Maybe you will get lucky.

If you keep the TV connected to the mini-displayport there is no mini-displayport-to-HDMI active adapter for that I am aware of. None are even listed in the "AMD Eyefinity Validated Dongles". You would also then need an active adapter for the DVI to mini-displayport connection. For the 27" screen the only adapter/converter that I know of for that is,

Atlona (Dual Link) DVI to Mini DisplayPort Converter

Not cheap. And that still leaves figuring out how to connect the TV with an active adapter.

I think I've given you all the information I can on this. You will have to decide what to try to do. When I was first investigating this I spent a lot of time google searching for "X-to-Y adapters" and "X-to-Y active adaptrs" for various X's and Y's to see what I could turn up. You may end up doing the same.

VGA to the TV? I just took it for granted you wanted to use the TV for viewing HD video with audio.

Just so I understand what you have.

1, You have one 27" directly connected to a mini-displayport.

2. You have the TV connected to a VGA-to-mini-displayport adapter on the second mini-displayport. That counts as one of the active adapters.

3. The second 27" display is connected to the remaining DVI port with what kind of adapter?

I thought both displays were apple 27" mini-displayport displays.

So you basically "got away with" essentially a single "active" adapter (vga adapter considered "active"). I had that in the back of my mind when I was alluding to using the DVI & S/PDIF converter on the DVI port and saying you "might get lucky". There's a bit of "fuszzyness" about the two-active adapter requirements (unless the direct DVI connection is considered "active" which may be the case).

The other reason I questioned using an analog vga connection to the TV was that for actual video streaming using a digital connection like HDMI would produce a actual higher quality HD image. But for just monitor purposes, VGA is probably "good enough".

I have a similar question with a HDMI twist. I have the same card, but I am using 2 of these Mini DisplayPort to HDMI adapters to run a pair of these AOC monitors. These AOC monitors only have HDMI and VGA in. I am about to add a 3rd AOC monitor of the same model and want to make sure it works correctly. If I am reading this page correctly, I can keep my 2 current screens and add a 3rd of the same kind by adding a DVI-to-HDMI adapter out of my DVI connection and plugging into the HDMI on my new montor.

Is that correct? Or am I wrong?

Does it matter if the adapter is active or passive?

Thanks.

The adapters must be ACTIVE when using three displays. There are no acrive HDMI adapters

<http://support.amd.com/us/eyefinity/Pages/eyefinity-dongles.aspx>

You could use active DVI adapters with DVI to HDMI cables or adapters.