Crossfire + Dual Monitor = no go?

[kakashisensei]

I have 2 4850s (both not similiar and also non-reference pcb design). One is Diamond (GeCube) and the other is HIS. I am running windows 7 (7100) x64 and using Cat 9.5.

Whenever I try to run a full screen game w/ crossfire enabled, it starts flickering on both screens and crashes, or it simply crashes.

W/ crossfire off, it works fine. W/ the 2nd monitor disabled and crossfire enabled, it works fine.

Crossfire is working fine. I tested it using 3d vantage and cod4 and there is much higher score / fps with crossfire on.


Some side things to note are:
The Diamond card came with a bios in which the crossfire tab didn't show up in CCC, so I had to downgrade to early bios to fix that. I am only using one xfire bridge connector, the one closest to the end of the card. This is because I only have one ribbon cable and both cards have accelero S1 coolers, making it very hard to connect the inside bridge.

Also using Display Fusion for 2 seperate wallpaper functions across both monitors, but I turned off this app and still got the problem.

Is this already a known problem or seems to be an isolated case?

 

[TotalLamer]

Might be a specific problem with your rig... I haven't had any flashing issues on the secondary screen even while playing a variety of games, everything from WoW to Crysis.

 

[LOUISSSSS]

i dont know the specific problem with your system, but yes, crossfire + dual monitor works and has been working since crossfire was out.

 

[kakashisensei]

Upon further testing, I have narrowed the problem. The problem seems to be the monitor pairing. I have updated the bios of the older 4850, but that didn't change anything.

One monitor is a 23" acer 1920x1080 16x9 aspect ratio. The other is 20.1" dell 2005fpw 1680x1050 16x10 aspect ratio. With the 23" acer as the main monitor, any full-screen game app crashes upon loading. With the 20" dell as the main monitor, crossfire works fine.

When I pair the dell w/ a spare 22" acer 1680x1050 16x10 monitor, it still crashes if he acer is the main monitor.

When I pair the acers together, it works fine.

I am totally stumped. At first I thought it was the aspect ratio difference, but the spare acer is 16x10, some review sites say it was 16x9 but it definitely looks 16x10 to me.

What do you guys think could be the problem?