First, the config:
- 2 x Sapphire reference 7970s
- 1 x MSI Lightning 7970 with 4 mini-DP ports
- 3 x Samsung S27A750D, connected by DP (so no adapters, just straight-through DP to DP from the MSI card)
- Umpteenth install of Win 7 pro
- Almost every 12.x series driver imaginable. Currently working with latest 9.00 beta drivers on a fresh install of Win 7.
The Problem
I've re-installed my OS roughly a half dozen times in the last few months as I experiment with various configs, and this one issue continually haunts me. When I first install Catalyst, I am able to create a 3x1 landscape Eyefinity group as normal. The issue I am regularly having is that at some point during my system build process, switching into Eyefinity no longer works. When I select "Create Eyefinity group" in CCC, it doesn't ask me for the primary monitor and skips straight to the layout. It then "creates" the group, meaning that it just switches to duplicate the display on all 3 monitors. Switching back to extended works fine. I've experienced this issue now across at least 4 builds of Win 7 and what has to be nearly a dozen different driver revs. Just for fun,
here's what my driver install folder looks like today.
Some other factors:
Happens with Crossfire enabled for 3 GPUs, 2 GPUs, or disabled
When it's working, everything is awesome. No tearing, and HD3D+Eyefinity works too.
I can usually make it work again with ATI Uninstaller. Using the normal uninstall process + reinstall won't do it. Driver Sweeper won't do it. I don't like ATI Uninstaller as it's a little aggressive, and I have reason to believe it may be the source of other, unrelated issues I have been experiencing.
System is otherwise stable. I've underclocked both CPU and RAM, and the video cards are currently running at stock clocks and the temps on everything look fine.