Crossfire 7870s and 3 screens

Evictus

Honorable
Sep 7, 2013
7
0
10,510
So I currently have two HD 7870s in a crossfire setup, running with two monitors (a 23 inch 1920x1080 and a 19.5 inch 1440x900) both plugged into a single GPU. The screen are plugged into the GPUs DVI and HDMI ports, but i still have two micro HDMI ports on the back of it. I just found another 19.5 inch screen (1440x900) and I wanted to run games over all three screens, using the smaller screens for the sides. I was just wondering if I had to do anything special besides plug the 3rd monitor in with a micro HDMI to HDMI cable. I read elsewhere about some active display port or something but I really couldn't understand it. Would it be better to break my crossfire setup and have my main screen in one GPU and the smaller screens both plugged into the other GPU? Or should I just have them all plugged into a single GPU?

CPU: Intel i7 3770k @4.2Ghz (H50 liquid cooling)
GPU: Gigabyte Radeon HD 7870 (x2 CF)
RAM: 8GB G.Skill DDR3 1600
PSU: Corsair 850w

I also realize its not ideal to have the screens have different resolutions and my larger monitor would be set to 1440x900 but i didn't mind that when i tested it with just the two screens i currently have.
 
Solution
my bad. you WILL need the active display port adaptor. it's necessary because of the aforementioned limitations to AMD graphics cards (though to be fair this has been a limitation dating back to ATI)
2 micro hdmi? don't you mean 2 micro display ports?

On a Radeon/AMD gpu, the gpu only natively supports 2 digital outputs. The mini display ports are for "additional" monitors. You use a mini/micro display port to hdmi or dvi or whatever adaptor, and it will work just fine with a 3rd monitor.