Eyefinity, Crossfire and me...

[rcs2k4]

Morning TR peeps, quick question. I want to run 3 monitors off my CF Radeons (spec in sig).

I have read that for this to work one screen needs to be display port connected. Is this right? My cards have 2 x DVI and 2 x HDMI per card, so I was hoping too connect 2 via HDMI and DVI the last.

Any advice apreciated as always

[mortifiedPenguin]

Yes, unless you have a custom card that explicitly allows this, you need to have at least one screen connected via DisplayPort. You can, however, use an active DisplayPort to DVI (then to HDMI or whatever, I suppose) to get around this. But, if you have a monitor that already supports DisplayPort, you might as well grab a cheap cable from Monoprice and not deal with the converters.

[rcs2k4]

Erm, interesting. Why does one have to be display port? I'm still attaching 3 cables (for simplicity, lets say 2 DVI-D and 1 HDMI) to a card. Thats 3 digital outputs, with 3 seperate connectors so why won't/can't all 3 displays get a picture. I'm missing something, because I dont get why the native attachment of say the HDMI on it's own wont work, but with a HDMI to DP active adaptor it will?

[MrJP]

Here's the info you need:
http://www.amd.com/us/products/technologies/amd-eyefinity-technology/how-to/Pages/faqs.aspx#multiple-display-requirements

The reason why you can't have more than two DVI/HDMI connections is because the card only has two TMDS transmitters. Adding a third would have been an unecessary cost for the vast majority of card buyers.

[rcs2k4]

Thanks for the info both, I now see why. I've also been a little dense... I looked up my card's specs, and what I thought were 2 HDMI's on the backside at quick glance, are actually one HDMI and one full-sized DP. Doh*.

Guess I connect 2 via DVI, and DP the 3rd one...

*DP and HDMI sockets look almost the same in my defence!!!