Multimonitor Difficulties in Crossfire Using 2 AMD Radeon HD7850s

Stuart Hamilton

Honorable
Mar 1, 2014
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10,510
Hey there,

I'm running two AMD Radeon HD7850s in CrossfireX configuration (bridged) on an ASUS P7P55LX motherboard, with Windows7 Ultimate x64, and recently decided to add a second monitor. I would like both monitors on DVI-D, and since I have two graphics boards I see no reason why I should have one digital and the other analog, as is most dual monitor setups.

Each monitor is connected to the DVI-D out on each graphics board, respectively, using DVI-D dual-link cables. I have tested both cables on the working DVI-D port, and they are both good.

Windows failed initially to detect the second monitor, completely. My immediate solution was to update Catalyst and drivers. During driver installation the second monitor was detected and displayed an extended desktop, and then went blank. After installation I rebooted and went back to Windows to detect the monitor again.

This is what came up:
Display_Problems.jpg


So, which is it? Is the monitor there? Or not? Windows seems to be confused, so I checked Catalyst, and Catalyst said: "Nope." The second monitor was not detected by Catalyst, yet during driver installation a signal was sent to the second monitor. I'm not sure if that constitutes "detection" but the monitor works.

Regarding CrossfireX. Crossfire is enabled, and functioning. I know this because I play PlanetSide 2 and use RadeonPro to force alternate frame rendering. Both GPUs are under load because both GPUs run at around 70 degrees under peak load, so I know that second GPU is active.

I'm going to grab a DVI-VGA adapter today, because I know it will work, but I would very much like a digital solution to this problem.
 
Solution
That's because in crossfire you only use the outputs on 1 card. The only way to use 2 cards and each of their outputs is to not crossfire them, they loosing their ability to increase gaming, but allows you to add more monitors.

In crossfire all displays have to be connected to the first card. NVidia cards I guess work different not AMD.
That's because in crossfire you only use the outputs on 1 card. The only way to use 2 cards and each of their outputs is to not crossfire them, they loosing their ability to increase gaming, but allows you to add more monitors.

In crossfire all displays have to be connected to the first card. NVidia cards I guess work different not AMD.
 
Solution

Stuart Hamilton

Honorable
Mar 1, 2014
5
0
10,510


Thank you! I was actually posting a notification to ignore this thread because I literally just found that out.

Thank you anyway for your help!